## nicole10 3 years ago true or false? In order to solve a system of equation by substitution, you MUST always solve for y in one of the equations and hen back-substitute

1. josecastaneda

True

2. josecastaneda

because for example if you have to unknowns and two equations, ex: y=x+5 and the other says x=y-6.....then you would have to back substitue the y=x+5 into the value for y in the second equation.

3. josecastaneda

|dw:1330406766557:dw|

4. josecastaneda

then just solve for x

5. nicole10

thank you i understand now

6. josecastaneda

|dw:1330406799210:dw|

7. nicole10

true or false? the x-intercept of the line with equation -3x+2y=5 is (-5/3,0)

8. josecastaneda

true

9. nicole10

i dont understand

10. josecastaneda

because to find the x intercept you have to set the y intercept to 0

11. mathg8

The previous problem was False ... you can solve for x and back substitute also !

12. mathg8

it doesn't matter for which variable you're solving

13. josecastaneda

? if you have and equation with two unknows you wont be able to solve for x....for ex: y=x+5, solve for x? you cant

14. josecastaneda

your gonna have to back substitute

15. josecastaneda

for the second equation

16. nicole10

how do you get -5/3 for x i am getting -5

17. josecastaneda

|dw:1330407174168:dw|

18. josecastaneda

and your y would be 0

19. jerwyn_gayo

in finding the y-intercept, assume that the value of x is zero, or vice versa. .

true or false? In order to solve a system of equation by substitution, you MUST always solve for y in one of the equations and hen back-substitute The answer is false. And as far as y=x+5 you can solver for x. getting x=y-5 You can solve for either x or y (assuming you have two equations with two unknowns x, and y. Choosing the one that is most convenient and then substitute the value found in the remaining unknown.