Question

Y=-3x + 10
y = -2x + 6
Substitution method

Answer 1

x=4 and y=−2

Explanation:

y=−3x+10;y=−2x+6

Step: Solve y=−3x+10for y:

Step: Substitute−3x+10foryiny=−2x+6:

y=−2x+6

−3x+10=−2x+6

−3x+10+2x=−2x+6+2x(Add 2x to both sides)

−x+10=6

−x+10+−10=6+−10(Add -10 to both sides)

−x=−4

-x/-1 = -4/-1 (Divide both sides by -1)

x=4

Step: Substitute4forxiny=−3x+10:

y=−3x+10

y=(−3)(4)+10

y=−2(Simplify both sides of the equation)

Answer 2

Solution is the point (4, -2)

Explanation:

use the expression for y from the first equation in the second equation:

then the equation y = - 2 x + 6 becomes:

- 3 x + 10 = - 2 x + 6

add 3 x to both sides

10 = 3 x - 2 x + 6

10 = x + 6

subtract 6 from both sides

x = 4

Now replace x with 4 in the first equation to find y:

y = - 3 x + 10 = - 3 (4) + 10 = - 12 + 10 = -2

Therefore this is the point solution to the system:

(4, -2)