Answer:
x=-1 1/4
Step-by-step explanation:
To find the intersecting point, you have to put the two formulas equal to each other
First isolate the same variable, in this case y
So y=x-4
Now we can say
2x + 7 = x - 4
Now solve for x
X= 3
Now fill this in in either one of the formulas
Y= 2 (3) + 7
Y= 13
So they’ll intersect at (3,13)
She’s basically repeating the process over with the same numbers, so just add up 3 and 2 how many ever times to get 20 and then add the 5 and divide.
8x + 7y = 19
- 8x
7y = 19 - 8x
÷ 7
y = 2 5/7 - 8/7x
So if that line is perpendicular to the line you're looking for, then the gradient (x value/slope) is the negative reciprocal to the gradient you're looking for, which would then be 7/8. You are told it has a y intercept of -7, so your final answer is:
y = -7/8x - 7
Hope this helps!