1963 TMTA High School Algebra I Contest Problem 23

Problem

On the graph chart, if the lines $y+5x+24=0$ and $y+x+4=0$ were graphed, at which point would they intersect?

1963 Algebra I 22.PNG

$\text{(A)} \quad A \quad \text{(B)} \quad B \quad \text{(C)} \quad D \quad \text{(D)} \quad E \quad \text{(E)} \quad F$

Solution

In slope-intercept form, we have two lines $y=-5x-24$ and $y=-x-4.$ Setting them equal to each other, we get \[-5x-24=-x-4 \rightarrow \boxed{x=-5}.\] The only point with an $x$ coordinate of $-5$ is $\boxed{\text{(C)} \quad D.}$

See Also

1963 TMTA High School Mathematics Contests (Problems)
Preceded by
Problem 22
TMTA High School Mathematics Contest Past Problems/Solutions Followed by
Problem 24