Question

设a.b是有理数，且a.b满足等式a^2+2b+√2*b=17-4√2，求的值

求a+b的值

Answer 1

a^2+2b+√2*b=17-4√2
a^2+2b=17
b=-4
a=正负5
a+b=-9 or 1

Answer 2

因为ab是有理数。无理向只有√2*b和右边的4√2所以b=-4.
a^2+2b=17.把b=-2带入。a=-5或者+5.