Question

1用适当方法解下列方程y平方-17y+30=0 y平方-7y-60=0 x平方+10x-11=0 x平方-12x-28=

Answer 1

y²-17y+30=0

(y-15)(y-2)=0

y=15或y=2

y²-7y-60=0

(y-12)(y+5)=0

y=12或y=-5

x²+10x-11=0

(x+11)(x-1)=0

x=-11或x=1

x²-12x-28=0

(x-14)(x+2)=0

x=14或x=-2