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3 years ago

8z-13=7 what's the number that replaces z

Mathematics

2 answers:

jekas [21]3 years ago

8 0

8z-13=7 (first, add 13 to both sides)
8z=20
z=20/8
=10/4
=5/2
=2.5

Goshia [24]3 years ago

4 0

All you do is solve for z. So 8z-13=7. To solve for a variable you have to do the opposite to cancel out the numbers on each side. First you add 13 over to 7 to cancel out 13 on the z side. So 8z=20 is what you have left. Then you divide 8 on both sides to cancel out 8 on the z side. what you are left with is z=2.5. Lastly you plug and check. 8(2.5) - 13 = 7, 20-13=7. And thats correct so z is 2.5.

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Farah rolls a fair dice and flips a fair coin. What is the probability of obtaining a 5 and a head?

Illusion [34]

Answer:

2/3 or 4/6

Step-by-step explanation:

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3 years ago

If the circle below is cut from the square of plywood below, how many square inches of plywood would be left over? Use π = 3.14,

Elis [28]

Answer:

86in²

Step-by-step explanation:

Find the complete question attached

Area of the circle = πr²

Area of the square = L²

Length of the side of the square

r is the radius of the circle

r = L/2 = 20/2 =10in

Given

Length of the side of the circle = 20in

Area of the square = 20²

Area of the square = 400in²

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Area of the circle = 3.14(100)

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3 years ago

How many weeks are there in 81 days

natima [27]

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If you have any questions, corrections, or problems, let me know. I hope this helped

4 0

2 years ago

Lines a and b are parallel. What is the measure of angle s? Enter your answer in the box. s = ∘∘ Horizontal parallel lines a and

VashaNatasha [74]

s = 22 degrees

Assuming I'm interpreting your description accurately, the top right angle of line b will also be 158 degrees because it's a corresponding angle to the top right angle of line a. That means that the top left angle of line b will be a supplementary angle. And supplementary angles add up to 180. So 180 - 158 = 22.

8 0

3 years ago

Read 2 more answers

According to the College Board website, the scores on the math part of the SAT (SAT-M) in a recent year had a mean of 507 and st

Leviafan [203]

Answer:

The actual SAT-M score marking the 98th percentile is 735.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this problem, we have that:

$\mu = 507, \sigma = 111$

Find the actual SAT-M score marking the 98th percentile

This is X when Z has a pvalue of 0.98. So it is X when Z = 2.054. So

$Z = \frac{X - \mu}{\sigma}$

$2.054 = \frac{X - 507}{111}$

$X - 507 = 2.054*111$

$X = 735$

8 0

3 years ago