Home
Class 7
MATHS
Find the value of a^(2)+b^(2) if a+b=10a...

Find the value of `a^(2)+b^(2)` if `a+b=10anda-b=2`.

Text Solution

AI Generated Solution

The correct Answer is:
To find the value of \( a^2 + b^2 \) given the equations \( a + b = 10 \) and \( a - b = 2 \), we can follow these steps: ### Step 1: Square both equations We start with the two equations: 1. \( a + b = 10 \) 2. \( a - b = 2 \) Now, we square both equations. - For the first equation: \[ (a + b)^2 = 10^2 \] This expands to: \[ a^2 + 2ab + b^2 = 100 \quad \text{(Equation 1)} \] - For the second equation: \[ (a - b)^2 = 2^2 \] This expands to: \[ a^2 - 2ab + b^2 = 4 \quad \text{(Equation 2)} \] ### Step 2: Add the two equations Now, we will add Equation 1 and Equation 2: \[ (a^2 + 2ab + b^2) + (a^2 - 2ab + b^2) = 100 + 4 \] ### Step 3: Simplify the left side On the left side, the \( 2ab \) and \( -2ab \) cancel each other out: \[ a^2 + a^2 + b^2 + b^2 = 104 \] This simplifies to: \[ 2a^2 + 2b^2 = 104 \] ### Step 4: Divide by 2 Next, we divide the entire equation by 2 to isolate \( a^2 + b^2 \): \[ a^2 + b^2 = \frac{104}{2} \] This gives us: \[ a^2 + b^2 = 52 \] ### Final Answer Thus, the value of \( a^2 + b^2 \) is \( \boxed{52} \). ---
Promotional Banner

Topper's Solved these Questions

  • ALGEBRIC IDENTITIES

    S CHAND IIT JEE FOUNDATION|Exercise Question Bank-7|40 Videos
  • ALGEBRIC IDENTITIES

    S CHAND IIT JEE FOUNDATION|Exercise Self Assessment Sheet-7|10 Videos
  • ALGEBRAIC EXPRESSIONS

    S CHAND IIT JEE FOUNDATION|Exercise SELF ASSESSMENT SHEET-17|1 Videos
  • AVERAGE

    S CHAND IIT JEE FOUNDATION|Exercise UNIT TEST -3 |20 Videos

Similar Questions

Explore conceptually related problems

Find the value of - (2a+3b) (2a-3b)

If (a+ib)=i^(i-oo), find the value of a^(2)+b^(2) and (b)/(a).

If a+b=10 and ab=16 find the value of a^(2)-ab+b^(2) and a^(2)+ab+b^(2)

If a+b=10 and ab-=16, find the value of a^(2)-ab+b^(2) and a^(2)+ab+b^(2)

If a+b=10 and ab=16 then find the value of a^2+2b^2 and a^2+ab+b^2

If ( a -b ) : ( a + b ) = 1/5 , find the value of ( a^2 - b^2 ) : ( a^2 + b^2 )

Find the value of ( a^2/b^2 + b^2/a^2 ) is ( a ) ( a/b + b/a )^2 - 2 ( b ) ( a/b + b/a )^2 + 2 ( c ) ( a/b + b/a )^2 + 4 ( d ) ( a/b + b/a )^2 - 4

If a=2,b=-2 find the value of a^2-b^2