Answer:
x=15
Step-by-step explanation:
21:2x=7:10 can be rewritten as 21/2x=7/10
21/2x=7/10, cross multiply
= 14x=210
x=15
That equals <u>.0124031008</u>
X² + 10x +2 = 0 .Complete the square of (x² + 10x + ??)
We know that (10x) is equal to twice the square root of the 1st (x) by ??
10x = 2.x.(??) and ?? = 5 and its square is 25. Then I have to add 25 and subtract 25 so that not to change the equation:
(x² + 10x + 25) -25 +2 =0
(x+5)² -23
Answer:
x=13,y=0
Step-by-step explanation:
We are given a system of equations

For equation 1,square all terms to reduce it
√x²+√y²=169
x+y=13
Make x the subject as required by the question to use substitution method
x=13-y
Plug x=13-y into eqn 2
3(13-y)+2y=39
39-3y+2y=39
39-y=39
y=39-39=0
Plug y=0 into equation 1
x+0=13
x=0