Question

I NEED HELP ASAP PLZ!!!
1) which ordered pairs in the form (x,y) are solutions to the equation 3x-4y=21
A.(-3,3)
B.(7,0)
C. (-1 ,6)
D.(11,3)
2) which statement about the ordered pairs (2, -9) and (3, -6) is true for the equation 5x-ydivided by 3=13?
A.(2, -9) is a solution to the equation.
B.both ordered pairs are the solutions.
C.(3, -6) is a solution to the equation.
D.neither pair is the solution.
4) what is the x intercept of the line of this equation? 1/3x+y=-15
enter answer in the box ( blank,0)

Answer 1

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)