Solve 490b^4-160b^2

$$490 b ^ { 4 } - 160 b ^ { 2 }$$

Factor

$$10\left(7b-4\right)\left(7b+4\right)b^{2}$$

Solution Steps

Factor out 10.

$$10\left(49b^{4}-16b^{2}\right)$$

Consider 49b^{4}-16b^{2}. Factor out b^{2}.

$$b^{2}\left(49b^{2}-16\right)$$

Consider 49b^{2}-16. Rewrite 49b^{2}-16 as \left(7b\right)^{2}-4^{2}. The difference of squares can be factored using the rule: p^{2}-q^{2}=\left(p-q\right)\left(p+q\right).

$$\left(7b-4\right)\left(7b+4\right)$$

Rewrite the complete factored expression.

$$10b^{2}\left(7b-4\right)\left(7b+4\right)$$

Evaluate

$$490b^{4}-160b^{2}$$