I assume that you meant RS and ST are segments of RT. If that is true then:
RS+ST=RT, using the values for these given...
8y+4+4y+8=36 combine like terms on left side
12y+12=36 subtract 12 from both sides
12y=24 divide both sides by 12
y=2
Answer: y = (-4/5)x + 8
Solution
The equation of line is
y = mx + b
Where
y = y coordinate
m = slope
x = x coordinate
b = y intercept
In order to write the equation of line we need to find the y-intercept (b)
substitute the slope (-4/5) and coordinates given (0,8) ,
y = mx + b
8 = -4/5 (0) + b
8 = b
So,
y = (-4/5)x + 8
the answer to your question is c. -25
Length= 28
Width= 14
Work:
2(2x)+2(x)=84
4x+2x=84
6x=84
x=14
14x2=28 (length)
