Question

What is the x-coordinate at the point of intersection for these equations?

f(x) = 2.8x - 12
g(x) = 5.8x + 9
A) -7
B) -3
C) 3
D) 7

Answer 1

x=-7

Explanation:

what it is basically saying is:

2.8x-12=5.8x+9

so add 12 on both sides to eliminate the -12

which will leave with:

2.8x=5.8x+21

Now we have to eliminate 5.8x so subtract 5.8x on both sides which leaves us with:

-3x=21 (because 2.8-5.8=-3 and 5.8-5.8=0)

so now we divide both sides by -3 which leaves us with:

x=-7 (because 21 divided by 3 equals 7 so 21 divided by -3 equals -7)

Answer 2

A) x = -7 .

Explanation:

Given : f(x) = 2.8x - 12

g(x) = 5.8x + 9.

To find : What is the x-coordinate at the point of intersection for these equations.

Solution : We have given that

y = 2.8x - 12 ------- ( equation 1)

y = 5.8x + 9--------( equation 2)

On subtracting equation 2 from equation 1.

y = 2.8x - 12

(-)y = (-)5.8x +(-) 9

______________

0= - 3x - 21

On adding 21 both sides

21 = -3x

On dividing both sides by -3 and switching sides .

x = -7 .

Therefore, x = -7 .