Answer
$77-31\sqrt7$
Work Step by Step
$(7-2\sqrt7)(5-3\sqrt7)$
Use the FOIL method to multiply the binomial.
Multiply the First terms, the Outside terms, the Inside terms, and the Last terms.
$(7\times5)+(7\times(-3)\sqrt7)+(5\times(-2)\sqrt7)+((-2)\sqrt7\times(-3)\sqrt7)$
Simplify.
$35-21\sqrt7-10\sqrt7+42$
Combine lik terms/like radicals.
$77-31\sqrt7$
