Karim is solving the quadratic equation x² + 5x-24 = 0 by grouping. His work is shown below. Determine the first
step at which Karim makes an error.
Step 1: x² + 8x + (-3x) - 24 = 0
Step 2: (x² + 8x) + (-3x - 24) = 0
Step 3: x(x+8) + 3(x+8)=0
Step 4: (+8)(x+3) = 0
Step 5: x+8 = 0 or +3=0
x = -8 or x = -3
Karim makes an error at Step 4: (+8)(x+3) = 0.
The correct equation after Step 3 should be: (x + 8)(x + (-3)) = 0.
Karim incorrectly adds a positive sign (+) before the 8 in Step 4. The correct equation should be: (x - 8)(x + 3) = 0.