Book Online Demo
Check Your IQ
Try Test

Courses

Dropper NEET CourseDropper JEE CourseClass - 12 NEET CourseClass - 12 JEE CourseClass - 11 NEET CourseClass - 11 JEE CourseClass - 10 Foundation NEET CourseClass - 10 Foundation JEE CourseClass - 10 CBSE CourseClass - 9 Foundation NEET CourseClass - 9 Foundation JEE CourseClass -9 CBSE CourseClass - 8 CBSE CourseClass - 7 CBSE CourseClass - 6 CBSE Course

Q.

The value of the expression (7.8) 2 − (2.2) 2 is [[1]].


see full answer

Start JEE / NEET / Foundation preparation at rupees 99/day !!

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!
An Intiative by Sri Chaitanya

answer is 56.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

detailed_solution_thumbnail
The value of the expression (7.8) 2 − (2.2) 2 is 56.
An expression is given as (7.8) 2 − (2.2) 2 , and it is asked to evaluate it.
It can be observed that the expression is of the general form a 2 − b 2 ,
where a=7.8 and b=2.2 .
To evaluate this expression, we use the identity a 2 − b 2 = a+b a−b , and then simplify the expression.
So, using the identity, the given expression can be written as follows,
(7.8) 2 − (2.2) 2 = 7.8+2.2 7.8−2.2
7.8 2 − 2.2 2 = 5.6 10 =56
Therefore, the expression (7.8) 2 − (2.2) 2 , is evaluated and the final value is obtained as 56 .
 
Watch 3-min video & get full concept clarity
Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
How to Join IIT after 10th
score_test_img

Get Expert Academic Guidance – Connect with a Counselor Today!

Related Blogs
Get ₹ 1 crore* worth scholarship for JEE / NEET / Foundation
Result Producing online coaching for JEE/NEET of south India
Largest All India Test Series for JEE/NEET
Best Books for IIT JEE
Best Books for NEET
How to Join IIT after 10th
whats app icon
The value of the expression (7.8) 2 − (2.2) 2 is [[1]].