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chapter2.7b
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1993-09-24
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àï2.7èExponents and the Order of Operations.
äèPlease insert the correct symbol between the two numbers
êê to make a true sentence.
âSêêêï2ë1êë13ë19
#ê 1)ï3ï?ï27ê2)ï─ï?ï─ê 3)ï──ï?ï──
êêêêè3ë2êë14ë21
êë3ï<ï27
êêêêè2ë1êë13ë19
#êêêêè─ï>ï─êë──ï>ï──
êêêêè3ë2êë14ë21
éS The number that occurs further to the left on the number line
is the smaller of the two numbers.ïThe symbol, "<" , is used to
represent "smaller than".ïThus, since 3 occurs to the left of 27 on
the number line, the correct symbol is "<".
êêêêè 3ï<ï27
Since 1/2 occurs to the left of 2/3 on the number line, it is the
smaller of the two numbers. The symbol, ">" ,is used to represent
"larger than".ïThus, the number 2/3 is larger than 1/2.
êêêêè 2ë1
#êêêêè ─ï>ï─
êêêêè 3ë2
This can be seen more clearly by expressing the numbers as equivalent
fractions with common denominators.ïSince 2/3 is equal to 4/6 and
1/2 is equal to 3/6, it is seen that 2/3 is greater than 1/2.
êêë 2ê4ë3ê1
#êêë ─è=è─ï>ï─è=è─
êêë 3ê6ë6ê2
1êêêêêè13ê19
#êëInsert the correct symbol betweenï──ïandï──.
êêêêêêë20ê20
ë 13ë19êè 13ë19êë19ë13
#ïA)ï──ï>ï──êB)ï──ï<ï──ê C)ï──ï<ï──êD)ïå
ë 20ë20êè 20ë20êë20ë20
ü
êêêêè13ë19
#êêêêè──ï<ï──
êêêêè20ë20
Ç B
2êêêêêè3ê 6
#êëInsert the correct symbol betweenï─ïandï──.
êêêêêêë8ê15
ê6ë3êè 3ë 6êë3ë 6
#ïA)ï──ï>ï─êB)ï─ï>ï──ê C)ï─ï<ï──êD)ïå
ë 15ë8êè 8ë15êë8ë15
ü
êè The least common denominator of 8 and 15 is 120.
ë 3ë 6êï45ë 48êï45ë 48ê 3ë 6
#ë ─ï?ï── ,ë ───ï?ï─── ,ë ───ï<ï───è soï─ï<ï──
ë 8ë15ê 120ë120ê 120ë120ê 8ë15
Ç C
3êêêêêè3ê5
#êëInsert the correct symbol betweenï─ïandï─.
êêêêêêë4ê8
ê3ë5êè 3ë5êë 5ë3
#ïA)è─ï>ï─êB)ï─ï<ï─êïC)ï─ï>ï─ê D)ïå
ê4ë8êè 4ë8êë 8ë4
ü
êëThe least common denominator of 4 and 8 is 8.
ë 3ë5êè 6ë5êë6ë5êï3ë5
#ë ─ï?ï─ ,êï─ï?ï─ ,êè─ï>ï─ësoï─ï>ï─
ë 4ë8êè 8ë8êë8ë8êï4ë8
Ç A
4êêêêêè2ê3
#êëInsert the correct symbol betweenï─ïandï─.
êêêêêêë5ê8
ê2ë3êè 3ë2êë 2ë3
#ïA)è─ï>ï─êB)ï─ï>ï─êïC)ï─ï<ï─ê D)ïå
ê5ë8êè 8ë5êë 5ë8
ü
êëThe least common denominator of 5 and 8 is 40.
ë 2ë3êè16ë15êè16ë15ê 2ë3
#ë ─ï?ï─ ,ê ──ï?ï──,êï──ï>ï──è soï─ï>ï─
ë 5ë8êè40ë40êè40ë40ê 5ë8
Ç A
5êêêêêè5ê 7
#êëInsert the correct symbol between ──ïandï──.
êêêêêêè 24ê30
ê7ë 5êè 5ë 7êë 5ë 7
#ïA)ï──ï<ï──ë B)ï──ï>ï──ê C)ï──ï<ï──êD)ïå
ë 30ë24êè24ë30êë24ë30
ü
êëThe least common denominator of 24 and 30 is 120
ë 5ë 7êï25ë 28êï25ë 28ê5ë 7
#ë──ï?ï──,ê───ï?ï───,ê───ï<ï───èso ──ï<ï──
ë24ë30ê 120ë120ê 120ë120ë 24ë30
Ç C
äè Please simplify the following fractions with exponents.
â
êêêêêêêè 1∙1∙1∙3∙3ë 9
# (1/2)Ä∙(3/5)ìï=ï(1/2)∙(1/2)∙(1/2)∙(3/5)∙(3/5)ï=ï─────────ï=ï───
êêêêêêêè 2∙2∙2∙5∙5ë200
#éS In order to simplify the expression,ï(1/2)Ä∙(3/5)ì, it is
necessary to write 1/2 as a factor three times and 3/5 as a factor
two times.êê 1è1è1è3è3
#êêêè ─ ∙ ─ ∙ ─ ∙ ─ ∙ ─
êêêè 2è2è2è5è5
Then, you can write this product as one fraction.
êêêêè1∙1∙1∙3∙3
#êêêêè─────────
êêêêè2∙2∙2∙5∙5
Finally, you can reduce and multiply the remaining factors.
êêêê3∙3êè 9
#êêêè ─────────è=è───
êêêè 2∙2∙2∙5∙5ê200
6
#êêêë Simplifyè (1/2)Ä
êè1êêè1êêè1
#ë A)ï─êë B)ï─êë C)ï─êë D)ïå
êè4êêè8êêè6
ü
êêêë 1è1è1êï1∙1∙1êï1
#êë(1/2)Äè =è ─ ∙ ─ ∙ ─è =è ─────è =è ─
êêêë 2è2è2êï2∙2∙2êï8
Ç B
7
#êêêë Simplifyè (3/4)ì
êè 9êêï6êêè9
#ë A)ï──êëB)ï─êë C)ï─êë D)ïå
êè16êêï8êêè4
ü
êêêë 3è3êï3∙3êè9
#êë(3/4)ìè =è ─ ∙ ─è =è ───è =è ──
êêêë 4è4êï4∙4êï16
Ç A
8
#êêêèSimplifyè (2/5)(1/3)ì
êè 4êêè8êêè2
#ë A)ï──êëB)ï──êëC)ï──êëD)ïå
êè15êêï15êêï45
ü
êêêë 2è1è1ê 2∙1∙1êè2
#ê(2/5)(1/3)ìè =è ─ ∙ ─ ∙ ─è=è ─────è =è ──
êêêë 5è3è3ê 5∙3∙3êï45
Ç C
9
#êêê Simplifyè (5/9)ì(18/25)ì
êè24êêêêê4
#ë A)ï──êëB)ï4êë C)ï──êëD)ïå
êè81êêêêë 25
ü
êêêêï5è5è18è18ê 2∙2êè4
#ê(5/9)ì(18/25)ìè =è ─ ∙ ─ ∙ ── ∙ ──è=è ───è =è ──
êêêêï9è9è25è25ê 5∙5êï25
Ç C
10
#êêë Simplifyè (2/7)ì(7/8)ì(8/9)
êè7êêè 1êêï56
#ë A)ï─êë B)ï──êëC)ï──êëD)ïå
êè9êêè18êêï89
ü
êêêê2è2è7è7è8êï1êè 1
#ï(2/7)ì(7/8)ì(8/9)è =è ─ ∙ ─ ∙ ─ ∙ ─ ∙ ─è=è ───è =è ──
êêêê7è7è8è8è9ê 2∙9êï18
Ç B
äè Please simplify the following expressions using the
êêïcorrect Order of Operations.
#âêêê 27ï÷ï(2ìï+ï5)
êêêêï27ï÷ï(4ï+ï5)
êêêêë27ï÷ï9
êêêêêï3
éSè Operations should be done in the following order:
êè 1)ïFirst, you should work inside any parençs.
êè 2)ïEvaluate any exponents.
êè 3)ïPerform all multiplication and division first come first
êê serve in order from left to right.
êè 4)ïFinally, perform all addition and subtraction first come
êê first serve in order from left to right.
#To simplify the expression, 27ï÷ï(2ìï+ï5), you would first work
inside the parençs and evaluate the exponent.
êêêê 27ï÷ï(4ï+ï5)
The next operation in the parençs is the addition.
êêêêè 27ï÷ï9
Since the operations inside the parençs have been completed, we can
perform the division.êï27ï÷ï9è=è3
#Thus, 27ï÷ï(2ìï+ï5)è=è3.ïThe same Order of Operations is used
when the numbers are fractions.
11
êêë Simplifyë10 - 18 ÷ 3 + 4
ë A)ï4êë B)ï8êêC)ï6êë D)ïå
üêêê 10 - 18 ÷ 3 + 4
êêêêè10 - 6 + 4
êêêêë 4 + 4
êêêêê 8
Ç B
12
#êêè Simplifyë(2Ä + 7) ÷ 5 + 4
êêêêêêë13
#ë A)ï7êë B)ï6êêC)ï──êëD)ïå
êêêêêêë 5
#üêêê(2Ä + 7) ÷ 5 + 4
êêêê(8 + 7) ÷ 5 + 4
êêêêï15 ÷ 5 + 4
êêêêë3 + 4
êêêêê7
Ç A
13êêê3ë 3ë2
#êêè Simplifyë─ï+ï──ï-ï─
êêêêè5ë10ë3
êè 7êêè4êêè 3
#ë A)ï──êëB)ï──êë C)ï──êëD)ïå
êè30êêï15êêè10
üë3è 3è2ê6 3è3ï3è10 2ê18è 9è20
#êè ─ + ── - ─è=è─∙─ + ─∙── - ──∙─è=è── + ── - ──è=
êè 5è10è3ê6 5è3 10è10 3ê30è30è30
êêï18 + 9 - 20ê27 - 20ê 7
#êêï───────────è=è───────è=è──
êêê30êê30êï30
Ç A
14êêê3ë 6ë4
#êêè Simplifyë─ï÷ï──ï+ï─
êêêêè5ë11ë5
êè13êêï17êêè19
#ë A)ï──êëB)ï──êë C)ï──êëD)ïå
êè10êêï10êêè10
ü
ë 3è 6è4ê3è11è4ê11è4ê11 + 8ê19
#ë ─ ÷ ── + ─è=è─ ∙ ── + ─è=è── + ─è=è──────è=è──
ë 5è11è5ê5è 6è5ê10è5êï10êï10
Ç C
15
#êêèSimplifyè (2/3)ì∙(1/5 + 3/10) ÷ 6/15
êè3êêè5êêè 2
#ë A)ï─êë B)ï─êë C)ï──êëD)ïå
êè7êêè9êêè15
#üêêï(2/3)ì∙(1/5 + 3/10) ÷ 6/15
#êêê (2/3)ì∙(2/10 + 3/10) ÷ 6/15
#êêêè (2/3)ì∙(5/10) ÷ 6/15
êêêè(4/9) ∙ (5/10) ÷ 6/15
êêêë4/9 ∙ 5/10 ∙ 15/6
êêêêè 4∙5∙15êï5
#êêêêè ──────è =è ─
êêêêè 9∙10∙6êï9
Ç B