math hlep!!!?

Question

multiplying radicals

root 8 * ( - root 18)

root 7 * root 8 = root 54 right?

- root 2 * 3 and root 8

Answer 1

sqrt(8) = sqrt(2² * 2) = sqrt(2²) * sqrt(2) = 2sqrt(2)

-sqrt(18) = -sqrt(3² * 2) = -3sqrt(2)

then sqrt(8) * (- sqrt(18)) = 2sqrt(2) * -3sqrt(2) = -6[(sqrt(2)]² = -6 * 2 = -12

more fastly here : sqrt(8) * -sqrt(18) = -sqrt(8 * 18) = -sqrt(144) = -12



sqrt(7) * sqrt(8) = sqrt(7*8) = sqrt(56) or 2sqrt(14)



sqrt(8) = 2sqrt(2)
then
-sqrt(2))* 3 + sqrt(8) = -3sqrt(2) + 2sqrt(2)
= -sqrt(2)

Answer 2

sqrt(8) * - sqrt(18) = - sqrt (144) = -12

sqrt(7) *sqrt(8) = sqrt(56) = 2 * sqrt(14)