14 8 7x=42解方程
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3X-X=42+422X=84X=84÷2X=42
令a=x2+x(a+1)(a+12)=42a2+13a+12=42a2+13a-30=0(a+15)(a-2)=0a=-15,a=2x2+x=-15x2+x+15=0无解x2+x=2x2+x-2=(x
x=1.5再答:x+4.5=6x=1.5再问:我要图再答:
5x=35x=7
(X(13-X)(X+(13-X)))/(X+1)=42得分母是X^2(13-X)+(13-X)X分子是(X+1)再得分母X(13-X)(X+1)分子分母抵消的(X+1)X=42得X=6
合并同类项10X=42相除X=4.2
42+X=3(X+12)42+X=3X+362X=6x=3
80%x+25%x=421.05x=42x=42÷1.05=40
x-2-17=42x=42+2+17x=61
2^x+(√2)^x=(√2)^2x+(√2)^x=42令t=(√2)^x,则方程变为t²+t-42=0﹙t>0﹚t=6,(√2)^x=6,2^x=36x=㏒2底36=2+2㏒2底3
x(x+1)=42x^2+x-42=0(x-7)(x+6)=0所以x-7=0或x+6=0即x=7,或x=-6
很简单的0.8x-6=420.8x-6+6=42+6x=48÷0.8x=60补充:
x/3+2/3=42x+2=42x=42-2x=40再问:哈、x/3哪来的再答:x/3就是三分之一X啊
56x=42(x+2)56x=42x+8456x-42x=8414x=84x=6
苍月Swart,你好:x-0.75x=420.25X=42X=42÷0.25X=168
2/3X+1/2X=42×64x+3x=42×67x=42×6X=36
8x+42=1788x=178-428x=136x=136÷8x=17
x+7/8x=42x*15/8=42x=42*8/15x=112/5