Question

PLEASE AGAIN MATH PLEASE HELP ME NUMBER 7-9 PLEASE!!!!

Answer 1

7.

The standard form: Ax + By = C

`a)\ y=(2)/(3)x-5\qquad\text{add 5 to both sides}\\\\y+5=(2)/(3)x\qquad\text{subtract y from both sides}\\\\5=(2)/(3)x-y\qquad\text{multiply both sides by 3}\\\\15=2x-3y\\\\\boxed{2x-3y=15}`

`b)\ (4)/(5)x-3y=10\qquad\text{myltiply both sides by 5}\\\\\boxed{4x-15y=50}`

`c)\ y-5=(1)/(2)(x-10)\qquad\text{multiply both sides by 2}\\\\2y-10=1(x-10)\\\\2y-10=x-10\qquad\text{add 10 to both sides}\\\\2y=x\qquad\text{subtract 2y from both sides}\\\\0=x-2y\\\\\boxed{x-2y=0}`

8.

The formula of a slope:

`m=(y_2-y_1)/(x_2-x_1)`

a) We have the points (-4, 7) and (8, -9). Substitute:

`m=(-9-7)/(8-(-4))=(-16)/(12)=-(4)/(3)\\\\\boxed{slope=-(4)/(3)}`

b) We have the points (-2, 7) and (-2, 5). Substitute:

`m=(5-7)/(-2-(-2))=(-2)/(0)\ \boxed{!}` division by 0!

slope is undefined

9.

a) The equation of a horizontal line: y = a (a - any real number)

We have the point (-5, 8) → x = -5 and y = 8

Answer: y = 8

b) The equation of a vertical line: x = a (a - any real number)

We have the point (-3, -2) → x = -3 and y = -2

Answer: x = -3