# grade 9 math slope equations

posted by on .

solve and comparison:

a)4x-9y=4
6x+15y=-13

im so lost!!!!!

• grade 9 math slope equations - ,

multiply the first by 3 to get
12x - 27y = 12 or 12x = 27y + 12

multiply the second by 2 to get
12x + 30y = -13 or 12x = -30y - 13

now "compare" the 12x of the first part with the 12x of the second part to get

27y + 12 = -30y - 13
etc.

"elimination" would be the more practical way of doing this one.
just subtract my two altered equations

• grade 9 math slope equations - ,

why do you hav to multiply it by three though?

• grade 9 math slope equations - ,

I wanted the x's to have the same coefficient.
4x .... and
6x ....

think of finding a "common denominator"

and remember, what I do to one side of any equation, I must do to the other side.

• grade 9 math slope equations - ,

thank u so much !!!!!!

• grade 9 math slope equations - ,

• grade 9 math slope equations - ,

Type the ordered pair that is the solution to these equations.3x - 2y = 8 2x + 5y = -1.