Question

(a-6)(a+6)-a(2a-3)=6-a2

Answer 1

Ответ:

a=14

Пошаговое объяснение:

$(a-6)(a+6)-a(2a-3)=6-a^2\\a^2-6a+6a-36-2a^2+3a=6-a^2\\-a^2+3a-36=6-a^2\\3a=42\\a=14$

Проверка:

$(14-6)(14+6)-14(14*2-3)=8*20-14*25=160-350=-190\\6-14^2=6-196=-190\\-190=-190$

Answer 2

Let's verify the given expression step by step:

1. Start with the left-hand side (LHS) expression: (a - 6)(a + 6) - a(2a - 3)

2. Expand the first bracket (a - 6)(a + 6): (a * a) + (a * 6) - (6 * a) - (6 * 6)

3. Simplify the first bracket: a^2 + 6a - 6a - 36

4. The middle terms (6a and -6a) cancel out: a^2 - 36

5. Now, expand the second bracket -a(2a - 3): -(a * 2a) + (a * 3)

6. Simplify the second bracket: -2a^2 + 3a

7. Now, we have the full left-hand side expression: a^2 - 36 - 2a^2 + 3a

8. Combine like terms: (a^2 - 2a^2) + 3a - 36

9. Simplify the expression: -a^2 + 3a - 36

So, the left-hand side (LHS) expression simplifies to -a^2 + 3a - 36.

Now, let's verify the right-hand side (RHS) expression, which is 6 - a^2:

Both the LHS and RHS expressions are equal to -a^2 + 3a - 36.

Hence, the given equation is true:

(a - 6)(a + 6) - a(2a - 3) = 6 - a^2