4a-8=28
add 8 to both sides to start to isolate the variable (a)
-8+8 cancels each other out
28+8=36
4a=36
to completely isolate the variable divide both sides by 4
4a÷4=a
36÷4=9
a=9
A^2 + b^2 = c^2
a^2 + (12)^2 = (13)^2
a^2 + 144 = 169
a^2 = 169 - 144
a^2 = 25
Sqrt (a^2) = Sqrt(25)
a = 5
Please mark brainliest if this helps
Answer:

Step-by-step explanation:
EF and JK are similar, and the other side we know, FG, is similar to KL. From there, just put them into a ratio!


Answer:
Step-by-step explanation:
Area of the rectangle =length * width
= 5 * 6 = 30 sq.inches
Answer:
y = 3x -18 (i added a graph)
Step-by-step explanation:
in order to find the slope you could do y2-y1/x2-x1
-6/4 - 3/7
-9/-3 = 3
and if you want to find the y-intercept:
-6 - 3 = -9
4 - 1 = 3
(3,-9)
-9 - 3 = -12
3 - 1 = 2
(2,-12)
-12 - 3 = -15
2 - 1 = 1
(1,-15)
-15 - 3 = -18
1 - 1 = 0
(0,-18)
therefore, the y-intercept is -18