Question 66

If $$9x^2+16y^2=60$$ and $$3x+4y=6$$, then the value of xy is

Solution

Share

Given : $$9x^2+16y^2=60$$ ------------(i)

and $$3x+4y=6$$

Squaring both sides, we get :

=> $$(3x+4y)^2=(6)^2$$

=> $$9x^2+16y^2+2(3x)(4y)=36$$

=> $$60+24xy=36$$     [Using (i)]

=> $$24xy=36-60=-24$$

=> $$xy=\frac{-24}{24}=-1$$

=> Ans - (A)

Was this solution helpful?

Get AI Help

View More Questions From Average, Ratio, and Proportions

Create a FREE account and get:

  • Free SSC Study Material - 18000 Questions
  • 230+ SSC previous papers with solutions PDF
  • 100+ SSC Online Tests for Free

Free SSC Quant Questions

SSC Data InterpretationSSC GeometrySSC Linear EquationsSSC Number SystemsSSC Quadratic EquationsSSC TrigonometrySSC AgesSSC Arithmetic

Join CAT 2026 course by 5-Time CAT 100%iler

Start your IIM journey with the right preparation and crack CAT 2026.

Enroll Now
Ask AI