## Algebra 1

$- \sqrt 2$
$4 \sqrt 50 - 7 \sqrt 18$ We rewrite the $\sqrt 50$ as $\sqrt (25 \times 2)$ because 25 and 2 are the factors of 50. We rewrite the $\sqrt 18$ as $\sqrt (9 \times 2)$ because 9 and 2 are the factors of 18. $4 \sqrt (25 \times 2) - 7 \sqrt (9 \times 2)$ *** Take the square root of 25 which is 5. Because 5 x 5 = 25 *** Take the square root of 9 which is 3. Because 3 x 3 = 9 $4 (5) \sqrt 2) - 7 (3) \sqrt 2$ $20 \sqrt 2) - 21 \sqrt 2$ The $\sqrt 2$ is common so we factor it out $\sqrt 2 (20-21)$ We subtract 20 and 21 and get -1. $\sqrt 2 (-1)$ $-\sqrt 2$