Question 1195183
linear equation is y = mx + b
m is the slope
b is the y-intercept
x is the number of gallons of fuel in the tank.
y is the weight of the airplane.
with a slope of 5.5, the equation becomes:
y = 5.5 * x + b
when x = 47, y = 2258.5
equation becomes:
2258.5 = 5.5 * 47 + b
solve for b to get:
b = 2258.5 - 5.5 * 47 = 2000.
the equation becomes:
y = 5.5 * x + 2000
2000 is the weight of the plane with no fuel in it.
when x = 47, the equation becomes:
y = 5.5 * 47 + 2000 = 2258.5.
this was the weight of the plane given in the statement of the problem, which confirms the equation is good.
with 13 gallons of fuel in it, the equation becomes:
y = 5.5 * 13 + 2000 = 2071.5
that's your solution.