Batas waktunya 30menit lagi

Batas waktunya 30menit lagi

Jawab:

1.A

$sqrt{7x-3} =5\7x-3=257x=25+3\7x=28\x=4\sqrt{7.5-3}=5\5=5\x=4$

$sqrt{x^{2} -4x-5}=x+7\x^2-4x-5=x^2+14x+49\-4x-5=14x+49\-4x-14x=49+5\-18x=54\x=-3$

$sqrt{3x+7}+sqrt{x+3}=8\sqrt{3x+7}=8-sqrt{x+3}\3x+7=64-16sqrt{x+3}+x+3\3x+7=67-16sqrt{x+3}+x\16sqrt{x+3}=67+x-3x-7\16sqrt{x+3}=60-2x\8sqrt{x+3}=30-x\x=6\x=118\8=8\30=8\,x=6 , x=118\x=6$

2.A. x∈(-∞,-4)∪(6,+∞)

B. x∈(-2,-1]∪[4,7)