Question

7ab – 5a – 28b + 20 plz tell answer

Answer 1

Answer:

(a-4) (7b-5)

Step-by-step explanation:

=(7ab-28b)-(5a-20)

=7b(a-4) -5(a-4)

=(a-4) (7b-5)

Always exhxange the variables looking at what can be divided by what, in this example, I switched -28b to 7ab because 1) 28 is divisible by 7 and 2) because they have atleast 1 same variable. In the other bracket, 20 is divisible by 5. In these types of questions, the 1st bracket must always have 2 varibles with 1 being divisible by the other and atleast 1 same variable. And in the 2nd bracket you must get atleast 1 number divisible by the other and the answer in the 2nd bracket must be the same as the 1st bracket. Hope this helps a lot

Answer 2

Given:

7ab - 5a -28b +20

To find :

Solve 7ab -5a -28b +20

Solution;

Factorization means when we break a never down into smaller numbers Multiplied together, we get an original number.

When a number is split into it's factors or divisors , it is called as factorization.

For example factors or divisors of 10 are 1, 2 and 5.

7ab -5a -28b +20

7 is divisor of 28.

5 is divisor of 20

hence putting the terms together

(7ab - 28 b ) + ( - 5a +20)

factorising the terms

( 7 x a x b ) - ( 7x 4 x b ) + ( - 5 x a + 5 x4)

taking common terms

7 b ( a - 4) - 5 ( a - 4)

( 7b -5) (a -4)

7ab -5a -28b +20 = ( 7b -5) (a -4)