1. (7 , 0) and (11 , 3) → B and D
substitute each coordinate point into the left side of the equation and if equal to 21 then it is a solution.
( 7 , 0) → (3 × 7) - ( 4× 0) = 21 - 0 = 21
(11 , 3) → (3 × 11 ) - ( 4 × 3) = 33 - 12 = 21
2. ( 2 , - 9 ) is a solution to the equation
substitute the coordinates into the equation and if equal to 13 the it is the solution.
(2 , - 9 ) → (5 × 2 ) - (-9)/3 = 10 + 9/3 = 10 + 3 = 13
(3 , - 6) → (5 × 3) - (- 6)/3 = 15 + 6/3 = 15 + 2 = 17
thus (2 , -9 ) is the solution
4. x- intercept = (- 45 , 0)
to find the x- intercept let y = 0
1/3 x + 0 = - 15
1/3x = - 15
multiply both sides by 3
x = 3 × - 15 = - 45
thus x -intercept = ( - 45 , 0)
