Step-by-step explanation:
We will solve this system of equations using two methods: elimination and substitution.
Method 1: Elimination
2x - y = -8. #1
-5x + y = 26. #2
Note that by adding these two equations, the y-variable is eliminated (thus the name) and you're only left with an equation with one variable. So upon adding, we get
-3x = 18 or x = -6
Using this value for x, put this back in either one of the equations. Let's use the 2nd one.
-5(-6) + y = 26
--> 30 + y = 26
Moving 30 to the right side, we get y = -4.
Method 2: Substitution
This is done by isolating one variable to the left side in one equation and then using it on the other equation. Let's take equation #2 and put the y-variable on the left side and you should get
y = 5x + 26
Now use this equation and plug it into the y in equation #1:
2x - (5x + 26) = -8
--> 2x - 5x - 26 = -8
--> -3x = 26 - 8 = 18 or <u>x</u><u> </u><u>=</u><u> </u><u>-</u><u>6</u><u>.</u>
Use this value for x into either one of the equations. Let's use equation #1 this time.
2(-6) - y = -8
--> -12 + 8 = y or <u>y</u><u> </u><u>=</u><u> </u><u>-4</u><u>.</u>
Notice that using either method will give you the same result, as one might expect.
Answer:
20
Step-by-step explanation:
Is there more to this question?
Triangles ABC and DEF may or may not be congruent, because the angle-angle-angle (AAA) postulate is not a criterion for congruency of any two triangles. This is because the angle-angle-angle postulate only incorporates the angles of the triangles, and the side lengths are not specified, so congruency may or may not be true for these triangles.
The y-value changes from 10 to 70 as the x-value changes from 0 to 10. That makes the slope (70 -10)/(10 -0) = 6, and the y-intercept = 10.
Selection A is the appropriate equation.
