Toán Lớp 9: giải phương trình
a) √-2x+1-5=0
b) 2 √9x-27-1/5 √25x-75-1/7- √49x-147=20
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 9: giải phương trình
a) √-2x+1-5=0
b) 2 √9x-27-1/5 √25x-75-1/7- √49x-147=20
Comments ( 1 )
$⇔\sqrt[]{-2x+1}=5$
$⇔-2x+1=25$
$⇔-2x=24$
$⇔x=-12,tm$
$⇔2\sqrt[]{9(x-3)}-\dfrac{1}{5}\sqrt[]{25(x-3)}-\dfrac{1}{7}\sqrt[]{49(x-3)}=20$
$⇔6\sqrt[]{x-3}-\sqrt[]{x-3}-\sqrt[]{x-3}=20$
$⇔4\sqrt[]{x-3}=20$
$⇔\sqrt[]{x-3}=5$
$⇔x-3=25$