If a fuel efficient car can go 210 miles on 4 gallons of fuel, how far can it go
on 12 gallons?

The distance covered by the car in 12 gallons of fuel is 630 miles.

Step-by-step explanation:

Distance covered by car in 4 gallons of fuel = 210 miles.

Let us use unitary method to find distance covered by car in 1 gallon of fuel.

Distance covered by car in 1 gallon of fuel = 210/4 miles.

Let us use unitary method to find distance covered by car in 12 gallon of fuel.

Distance covered by car in 12 gallons of fuel = (210/4)*12 = 630 miles.

15

step-by-step explanation:

infinitely many solutions

step-by-step explanation:

we have been given the equation;

2(2x + 3) = -4 + 2(2x + 5)

we need to determine the value of x.

2(2x + 3), we expand this expression to obtain 4x + 6

similarly 2(2x + 5) will become 4x + 10

now we have;

4x + 6 = -4 + 4x + 10

4x + 6 = 4x + 10 - 4

4x + 6 = 4x + 6

the expression on the left hand side is identical to the one on the right hand side. therefore, we are looking at just a single straight line whose equation is;

y = 4x + 6

consequently, we shall have infinitely many solutions