Hard Heart of Algebra Problem for the SAT

Today I would like to provide an example of a hard “Heart of Algebra” problem that could show up on the revised SAT.

Level 5 – Heart of Algebra

3x – 7y = 12
kx + 21y = -35

For which of the following values of k will the system of equations above have no solution?

(A)  9
(B)  3
(C) -3
(D) -9

Please feel free to post your solutions or attempted solutions in the comments below and we can discuss the best way to solve the problem. I will post solutions to this problem next week.

More Hard SAT Math Practice Problems

For many more hard SAT math problems like these, each with several fully explained solutions, check out the Get 800 collection of SAT math books. Click on the picture below for more information about these books.

If you think your friends would like to try this problem, please share:

Speak to you soon!

Comments

comments