(x^2+4)+(2x+4)-15=0
3个回答
(x^2+4)+(2x+4)-15=0
x²+2x+1+3+4-15=0
(x+1)²-8=0
(x+1)²=8
两边开方:
x+1=±2√2
x1=-1+2√2
x2=-1-2√2;
相关问题
解下列不等式组(1)4x²-27x+18>0 x²+4x+4>0 (2)3x²+x-2≥0 4x²-15x+9>0
(1)3x2-15=0(2)x2+4x-6=0(3)2x2-7x+3=0(4)(x+2)2-10(x+2)+24=0.
降次求方程的解:(1)x^2-4x+4=0 (2)5x^2-15x=0 (3)x^2-5x+6=0 (4) 2x^2-7
(x^2-4x)^2-2(x^2-4x)-15
x+3/0.15-x+4/0.2=1.6
解方程2(0.3X+4)-5(0.2x-7)=9 2(3y-4)+7(4-y)=4y 4(15-2x)-6x=16x-6
15.5-0.4(x+3)=3/4x-2/5(x-5)
f(x)=-2x^2-6x+15(-4小于x小于0)
3(x-7)-5(4-x)=15 0.2分之0.1x+0.3+2.5=0.4x-1
(1)(2x-1)2=9(2)x2-2x-4=0(3)(x-2)(x-5)=-2(4)x(x-3)=15-5x