Question

若m的2次方-n的2次方=6,且m-n=3,则m+n=?

若m的2次方-n的2次方=6,且m-n=3,则m+n=?
计算:(y的3次方)的2次方÷y的5次方=?
已知x的2次方-5x=14,求(x-1)(2x-1)-(x+1)的2次方+1的值.

Answer 1

1、因为m的2次方-n的二次方=6
即(m+n)(m-n)=6且m-n=3
所以m+n=2
2、原式=y6除以y5=y
3、原式=2x2-3x+1-x2-2x-1+1
=x2-5x+1=14+1=15

Answer 2

1.m的2次方-n的2次方=(m+n)(m-n)=6,因为m-n=3,所以m+n=2
2.原式=y的6次方/y的5次方=y
3.原式=x的2次方-5x+1=14+1=15.

Answer 3

m+n=2
(y的3次方)的2次方÷y的5次方=y
已知x的2次方-5x=14,(x-1)(2x-1)-(x+1)的2次方+1的值为15

Answer 4

m²-n²=(m+n)(m-n)
6=3(m+n)
m+n=2

(y³)²÷y^5
=y^(3×2-5)
=y

x²-5x=14
(x-1)(2x-1)-(x+1)²+1
=2x²-3x+1-x²-2x-1+1
=x²-5x+1
=14+1
=15

Answer 5

①(m+n)(m-n)=m²-n²
m+n=6/3=2
②(y³)²÷y^5=y^6÷y^5=y
③x²-5x=14
(x-1)(2x-1)-(x+1)²+1
=2x²-3x+1-x²-2x-1+1
=x²-5x+1
=14+1=15