Solve 25x ^ 2 - (5x - 9) ^ 2 = | Equatix - Math Solver

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Example

3(r+2s)=2t-4

a⋅(b-2)=3b

3(r+2s)=2t-4

a⋅(b-2)=3b

Question

$$25x^{2}-(5x-9)^{2}=$$

Evaluate

$90x-81$

Solution Steps

Use binomial theorem $\left(a-b\right)^{2}=a^{2}-2ab+b^{2}$ to expand $\left(5x-9\right)^{2}$.

$$25x^{2}-\left(25x^{2}-90x+81\right)$$

To find the opposite of $25x^{2}-90x+81$, find the opposite of each term.

$$25x^{2}-25x^{2}+90x-81$$

Combine $25x^{2}$ and $-25x^{2}$ to get $0$.

$$90x-81$$

Expand

$90x-81$

Solution Steps

Use binomial theorem $\left(a-b\right)^{2}=a^{2}-2ab+b^{2}$ to expand $\left(5x-9\right)^{2}$.

$$25x^{2}-\left(25x^{2}-90x+81\right)$$

To find the opposite of $25x^{2}-90x+81$, find the opposite of each term.

$$25x^{2}-25x^{2}+90x-81$$

Combine $25x^{2}$ and $-25x^{2}$ to get $0$.

$$90x-81$$