CUET Preparation Today
CUET
General Test
Quantitative Reasoning
Algebra
a2 + b2 = 41
x2 + y2 = 16
ax + by = 20
Find ay - bx:
13
17
16
15
Formula → (a2 + b2) (x2 + y2) = (ax + by)2 + (ay - bx)2
Let ay - bx = t
41 × 16 = (20)2 + t2
656 = 400 + t2
t = \(\sqrt {256}\) = 16
