How do you solve 3x plus 4y equals 120?

Answer 1

Get it in linear shape.

3X + 4Y = 120

4Y = -3X + 120

Y = -3/4X + 30

a line.

Slope = -3/4

y-intercept = 30

x-intercept = 40.

And that's as far as you can go. This doesn't "solve" anything. A 'solution' means

numbers for the variables that make the equation a true statement. You found a

line, and the (x, y) coordinates at every point on the line make the equation a true

statement. There are an infinite number of them.

An equation with two variables doesn't have a 'solution'. Its graph is a line.

Two equations with two variables have a solution ... the solution is the point

where the graphs (lines) of both of them intersect.