Put the following equation of a line into slope-intercept form, simplifying all fractions.

15, x, plus, 3, y, equals, 21
15x+3y=
21

In order to put the equation into slope-intercept form (y = mx + b), we need to solve for y.

Starting with the equation 15x + 3y = 21, we can isolate the y term by subtracting 15x from both sides of the equation:

3y = 21 - 15x

Next, we can simplify the right side:

3y = -15x + 21

Finally, divide both sides by 3 to solve for y:

y = (-15/3)x + 7

Thus, the equation in slope-intercept form is y = -5x + 7.