1) (√x - √y)(x + √xy + y)= (√x)(x) + (√x)(√xy) + (√x)(y) - (√y)(x) - (√y)(√xy) - (√y)(y)= x√x + x√xy + x√y - y√x - y√xy - y√y= x√x + x√x√y + x√y - y√x - y√x√y - y√y= x√x + √x^2y + x√y - y√x - √x*y - y√y= x√x + xy√y + x√y - y√x - xy - y√y
2) (5√t + 7)(25t - 35√t + 49)= (5√t)(25t) + (5√t)(-35√t) + (5√t)(49) + (7)(25t) + (7)(-35√t) + (7)*(49)= 125t√t - 175t + 245√t + 175t - 245√t + 343= 125t√t + 175t√t + 245√t - 245√t + 343= 300t√t + 343
1) (√x - √y)(x + √xy + y)
= (√x)(x) + (√x)(√xy) + (√x)(y) - (√y)(x) - (√y)(√xy) - (√y)(y)
= x√x + x√xy + x√y - y√x - y√xy - y√y
= x√x + x√x√y + x√y - y√x - y√x√y - y√y
= x√x + √x^2y + x√y - y√x - √x*y - y√y
= x√x + xy√y + x√y - y√x - xy - y√y
2) (5√t + 7)(25t - 35√t + 49)
= (5√t)(25t) + (5√t)(-35√t) + (5√t)(49) + (7)(25t) + (7)(-35√t) + (7)*(49)
= 125t√t - 175t + 245√t + 175t - 245√t + 343
= 125t√t + 175t√t + 245√t - 245√t + 343
= 300t√t + 343