81 ? +c= 5 4 ? start fraction, 1, divided by, 8, end fraction, plus, c, equals, start fraction, 4, divided by, 5, end fraction c=c=c, equals

7

Step-by-step explanation:

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70

b

step-by-step explanation:

the equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (3, - 5) ← 2 points on the line

m = = = - 3

with m = - 3 and (a, b) = (3, - 5), then

y - (- 5) = - 3(x - 3), that is

y + 5 = - 3(x - 3) → b