Toán Lớp 9: Tìm x không âm biết: a. √????= 3 b. √????= √5 c. √????= 0 d. √????= -2 e/ √????−2= 3 g/ √2????−1=5 h/ √????-3=0 giúp vs ạ

Question

Toán Lớp 9:  Tìm x không âm biết: a. √????= 3 b. √????= √5 c. √????= 0 d. √????= -2 e/ √????−2= 3 g/ √2????−1=5 h/ √????-3=0 giúp vs ạ

tuenhioanh · Answer

Giải đáp: a, sqrt{x} = 3 <=> ( sqrt{x})^2 = 3^2 <=> x = 9 b, sqrt{x} = sqrt{5} <=> ( sqrt{x})^2 = ( sqrt{5}) ^2 <=> x= 5 c, sqrt{x} = 0 <=> x= 0 d, sqrt{x} = -2 <=> x = 4 e, sqrt{x} - 2= 3 <=> sqrt{x} = 5 <=> ( sqrt{x})^2 = 5^2 <=> x= 25 g, sqrt{2x} - 1 = 5 <=> ( sqrt{2x})^2 = 6^2 <=> 2x = 36 <=> x= 18 h, sqrt{x} - 3= 0 <=>( sqrt{x})^2 = 3^2 <=> x= 9

chauhoangmy98 · Answer

a, &radic;x = 3   &hArr; x = 9   b, &radic;x = &radic;5   &hArr; x = 5   c, &radic;x = 0   &hArr; x = 0   d, &radic;x = -2   &hArr; x = &empty;   e, &radic;x - 2 = 3   &hArr; &radic;x = 3+2   &hArr; &radic;x = 5   &hArr; x = 25   g, &radic;2x - 1 = 5   &hArr; &radic;2x = 5 + 1   &hArr; &radic;2x = 6   &hArr; 2x = 36   &hArr; x = 18   h, &radic;x - 3 = 0   &hArr; &radic;x = 0 + 3   &hArr; &radic;x = 3   &hArr; x = 9