Question

X = 10

3x + 5y = 20
What is the solution (x,y) of the system of equations?

(y ? , x ? )

Answer 1

With x=10
This implies that 3(10)+5y=20

30+5y=20

5y=20-30

5y=-10

Divide through by 5

y=-2

Therefore (x,y) =(10,-2)

Answer 2

Note that:

• x = 10
• 3x + 5y = 20

Use system of equations to solve for x and y.

• x + 0y = 10

3x + 5y = 20

• 3x + 0y = 30

3x + 5y = 20

• 0y - 5y = 30 - 20
• => -5y = 10
• => y = -2

Substitute the value of y into any equation to find x.

• 3x + 5y = 20
• => 3x + 5(-2) = 20
• => 3x - 10 = 20
• => 3x = 30
• => x = 10

Put the solution in (x,y) form.

• (x,y) = (10,-2)

Hoped this helped!