sat suite question viewer

Algebra / Linear functions Difficulty: Medium

In the xy-plane, line k has a slope of 5 and a y-intercept of 0,-35. What is the x-coordinate of the x-intercept of line k ?

Back question 143 of 152 Next

Explanation

The correct answer is 7. An equation of a line in the xy-plane can be written in the form y=mx+b, where m is the slope of the line and (0,b) is the y-intercept of the line. It’s given that line k has a slope of 5 and a y-intercept of (0,35). Therefore, m=5 and b=35. Substituting 5 for m and 35 for b in the equation y=mx+b yields y=5x35. The x-intercept of a line in the xy-plane is the point where the line intersects the x-axis, which is a point with a y-coordinate of 0. Substituting 0 for y in the equation y=5x35 yields 0=5x35. Adding 35 to both sides of this equation yields 35=5x. Dividing both sides of this equation by 5 yields 7=x. Therefore, the x-coordinate of the x-intercept of line k is 7.