7 + 2y = 8x 3x - 2y = 0 Solve the system of equations by substitution. (70/3, 140/9) (7/5, 21/10) no solution coincident

1 answer:

5 0

So we have the system of equations:
$7+2y=8x$ equation (1)
$3x-2y=0$ equation (2)

To use substitution, we are going to solve for one variable in one of our equations, and then we are going to replace that value in the other equation:
Solving for $x$ in equation (2):
$3x-2y=0$
$3x=2y$
$x= \frac{2}{3}y$ equation (3)

Replacing equation (3) in equation (1):
$7+2y=8x$
$7+2y=8( \frac{2}{3} y)$
$7+2y= \frac{16}{3} y$
$7= \frac{10}{3} y$
$y= \frac{7}{ \frac{10}{3} }$
$y= \frac{21}{10}$ equation (4)

Replacing equation (4) in equation (3):
$x= \frac{2}{3}y$
$x=( \frac{2}{3} )( \frac{21}{10} )$
$x= \frac{7}{5}$

We can conclude that the solution of our system of equations is <span>(7/5, 21/10)</span>

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Answer:

A) answer c ; B) X+3.7=15.3 ; C) 15.3 - 3.7 = 11.6 ---> 11.6+3.7=15.3

Step-by-step explanation:

Solution for A: First you have to look for the line underneath the bar says 15.3 as this will represent the total amount of liters in the bucket altogether. This would be bar c since we also know that we have 3.7 liters added but are missing the amount that was previously inside the bucket.

Solution for B: Let X resemble the unknown amount of water. To solve B, we need to write an equation. We know that there was already an amount of water in the bucket prior to us pouring more in so X is our first addend. We then added 3.7 liters of water to the unknown amount so that is our next addend giving you X+3.7=15.3

Solution for C: Now that we know our equation, we do the inverse operation (subtraction) in order to figure out the missing amount of water. This means we do

15.3 - 3.7 = 11.6

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