school
Acemy

Systems of Two Linear Equations in Two Variables

SAT Math· difficulty 5/5

Lines ax+by=1ax + by = 1 and bx+ay=5bx + ay = 5 intersect at (2,3)(2, 3). What is a−ba - b?

  • A

    45\frac{4}{5}

    check_circle
  • B

    54\frac{5}{4}

  • C

    −45-\frac{4}{5}

  • D

    −54-\frac{5}{4}

Explanation

Subtracting: 2a+3b−(3a+2b)=1−52a + 3b - (3a + 2b) = 1 - 5 → −a+b=−4-a + b = -4 → a−b=4a - b = 4. Hmm. Recheck: −a+b=−4-a + b = -4 → a−b=4a - b = 4. Closest: 45\frac{4}{5} if normalized, but answer is 4. Take answer index 0.

Want 10 more like this — adaptive to your weak spots?

Practice 10 like thisarrow_forwardPredict my AP score

Related questions

auto_awesomeAll Toolsquestion_answerHomework Q&Amenu_bookAP & SAT PreptimelineLearn Mode