Solve this system of equations using
the substitution method.
y = 3x + 9
y = 5x – 3
i need the answer for x and y

First, when solving for x, you would need to make one of the equation into standard form, which would be Ax + By = C. So, I'm going to use y = 5x -3.

y = 5x - 3  || subtract -5x on both sides from the equal sign

5x + y = -3  || there you have one equation in standard form

Now, all you have to do now is substitute the y-intercept form equation into the standard form equation. As you can see, you would substitute the y-intercept form into the y in the standard form equation.

5x + y = -3

5x + 3x + 9 = -3  || combine like terms

8x + 9 = -3  || subtract 9 on both sides from the equal sign

8x = 6  || divide by 8 on both sides from the equal sign

x = 0.75  || final answer for x

Then for solving y, take any equation in y-intercept form and substitute with the x in the equation, which I'm going to use y = 3x + 9 in this case.

y = 3x + 9  || substitute with x

y = 3 (0.75) + 9  || multiply 3 and 0.75

y = 3.75 + 9  || add 3.75 and 9

y = 12.75  || final answer for y

Thus, x = 0.75 and y = 12.75.

7. d. 64

8. i. 32

9. c. 125

10. j. none of the above

11. d. 81

12. i. 216

13. e. none of the above

14. g. 240

15. e. none of the above

16. g. 32

17.   e. none of the above