Question

What is the solution to the system of equations below? y=-1/3x+9 and y=2/3x-12

(21,2)
(21,-10)
(-21,16)
(-21,-26)

Answer 1

The correct answer is first option (21, 2)

Explanation:

The given two equations are,

y=-1/3x+9 and y=2/3x-12

To find the solution

Two equations are

y=-1/3x+9 -------(1)

y=2/3x-12 -------- (2)

(2) - (1) ⇒ 0 = 3/3x + (-12 - 9)

⇒0 = x - 21

x = 21

Substitute value of x in eq(1) we get,

y = -1/3 * 21 + 9 = -7 + 9 = 2

Therefore the solution is (21, 2)

The correct answer is first option

Answer 2

The correct answer option is (21, 2).

Explanation:

We are given the following two equations and we are to find the solution to this system of equations:

`y=-(1)/(3) x+9` --- (1)

`y=(2)/(3) x-12` --- (2)

Since the left hand side of the both the equation is equal so we can equate the right hand sides of these equations equal to each other.

`-(1)/(3) x+9 = (2)/(3) x-12`

`(2)/(3) x+(1)/(3) x = 9+12`

x = 21

Substituting this value of x in (2) to find y:

`y=(2)/(3) (21) - 12`

y = 2