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3 years ago

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On four exams, Wallace’s grades were 79,93,91, and 68. What grade must he obtain on his fifth exam to have an 80 average?

2 answers:

neonofarm [45]3 years ago

7 0

(79 + 93 + 91 + 68 + x) / 5 = 80
(331 + x) / 5 = 80.....multiply both sides by 5
331 + x = 80 * 5
331 + x = 400
x = 400 - 331
x = 69 <=== he would have to make at least a 69

Leona [35]3 years ago

7 0

(79 + 93 + 91 + 68 + x) / 5 = 80

Simplify

(331 + x)/5 = 80

Multiply 5 to both sides to isolate the x.

331 + x = 400

Isolate the x. Subtract 331 from both sides

x + 331 (-331) = 400 (-331)

x = 69

69 is your answer

hope this helps

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Simplify (-2/5) divided by (8/9) times (2/9) divided by (-1/3) explain and show all steps

spayn [35]

Simplification of (-2/5) divided by (8/9) times (2/9) divided by (-1/3) is 0.3

<em><u>Solution:</u></em>

Given that,

Simplify (-2/5) divided by (8/9) times (2/9) divided by (-1/3)

Here "times" represent multiplication

<em><u>The above sentence can be written mathematically as:</u></em>

$\frac{-2}{5} \div \frac{8}{9} \times \frac{2}{9} \div \frac{-1}{3}$

Convert the problem to multiplication by changing the division sign to multiplication. When we change division sign to multiplication, the fraction becomes reciprocal

$\rightarrow \frac{-2}{5} \times \frac{9}{8} \times \frac{2}{9} \times \frac{3}{-1}$

Cancelling the common terms in numerator and denominator,

$\rightarrow \frac{-2}{5} \times \frac{1}{8} \times \frac{2}{1} \times \frac{3}{-1}$

Multiplying terms in numerator and denominator,

$\rightarrow \frac{-12}{-40}$

Negative sign in numerator and denominator cancels each other

$\rightarrow \frac{-12}{-40} = \frac{12}{40}$

Reducing to lowest terms we get,

$\rightarrow \frac{12}{40} = \frac{3}{10}$

In decimal form we get,

$\rightarrow \frac{3}{10} = 0.3$

Thus solution to given expression is 0.3

8 0

3 years ago

Mary bought 5/6 of a foot of blue ribbon and 2/3 of a foot of yellow ribbon. she used a combined total of 1/2 foot of ribbon to

djyliett [7]

Answer:

3/4

Step-by-step explanation:

2/3 = 4/6 so 5/6 plus 4/6 = 1 3/6 then divide by 2, it will give u 0.75 in decimal form which is simplifyed to 3/4, so 3/4 is the answer.

8 0

3 years ago

8(3+a)=64 what is a=?

8090 [49]

Answer:

5

Step-by-step explanation:

8(3 + a) = 64

3 + a = 8

a = 5

8 0

3 years ago

Read 2 more answers

Simplify the expression. Write your answer using decimals.

Andrei [34K]

Answer:

−2.5d−0.7

Step-by-step explanation:

1 Expand by distributing terms.

-(2.5d+5)+4.3

2 Remove parentheses.

-2.5d-5+4.3

3 Collect like terms.

-2.5d+(-5+4.3)

4 Simplify.

-2.5d-0.7

7 0

3 years ago

. only answer if you will actually help pls!!!!!!!!

xxMikexx [17]

Answer:

$5820$ square inches

Step-by-step explanation:

For the rectangular prism in the middle:

$24*30=720*2=1140$

$10*30=300*2=600$

$1140+600=1740$

For the left triangular prism:

$10*24=240$

$26*30=780$

$24*30=720$

$10*30=300$

$240+780+720+300=2040$

For the other right triangular prism, it's the same.

Let's add now to find the surface for the whole ramp.

$1740+2040+2040=5820$

Hope this is helpful to you

7 0

3 years ago