0

Guest

Courses New

Simplify 7x 2 (3x – 9) + 3 and find its values for x = 4 and x = 6

 Simplify 7x2(3x – 9) + 3 and find its values for x = 4 and x = 6

Grade:12

1 Answers

Harshit Singh
askIITians Faculty 5963 Points
3 years ago
Dear Student

7x^2 (3x – 9) + 3

Solve for 7x^2 (3x – 9)

= (7x^2× 3x) – (7x^2× 9) (using distributive law: a(b – c) = ab – ac)

= 21x^3– 63x^2

So, 7x^2 (3x – 9) + 3

= 21x^3– 63x^2+ 3

Now, for x = 4,

21x^3– 63x^2+ 3

= 21 × 43– 63 × 42+ 3

= 1344 – 1008 + 3

= 336 + 3 = 339

Now, for x = 6,

21x^3– 63x^2

= 21 × 63– 63 × 62+ 3

= 2268 + 3

= 2271


Thanks

Think You Can Provide A Better Answer ?

Other Related Questions on 8 grade maths

View all Questions »

ASK QUESTION

Get your questions answered by the expert for free

Answer and earn gift vouchers

Win Gift vouchers upto Rs 500/-

View courses by askIITians

Design classes One-on-One in your own way with Top IITians/Medical Professionals

Click Here Know More

Complete Self Study Package designed by Industry Leading Experts

Click Here Know More

Live 1-1 coding classes to unleash the Creator in your Child

Click Here Know More

a Complete All-in-One Study package Fully Loaded inside a Tablet!

Click Here Know More