Question

(2+ root 5 ) ( 5 - root 7 ) - (a)​

Answer 1

Answer:

(2 + √5) (5 - √7)

(2)(10) + (2)(-√7) + (√5)(5) + (√5)(-√7)

20 - 2√7 + 5√5 - √35

Confusion is how to multiply √5 and -√7. Learn radical expressions from YT.

√5 = 5^½

-1 × √7 = -1 × 7 ^½

So, √5 × -√7 ≡ -1 (5^½)(7^½)

Law of exponent:→ aⁿ × bⁿ = abⁿ.

So, -1 × (5 × 7)^½

-1 × 35^½

-1 × √35,

as power of ½ = √

Answer 2

first we have to multiple in the breaker so (2+√5) (5-√7) we get this answer 9.9727574822701.

and 9.9727574822701 - (a)

then we get the answer as -9.9727574822701a this the correct answer or we can write in -9.97a

I hope that it was help to you to learn and please mark this answer as brilliant answer please.