Let me see if I can decipher that :P
3/(3x)+1/x+4=10/(7x) first we need to make all terms have a common denominator of 21x...
(21+21+84x)/(21x)=30/(21x) multiplying both sides by 21x leaves you with
21+21+84x=30 combine like terms on left side
42+84x=30 subtract 42 from both sides
84x=-12 divide both sides by 84
x=-1/7
Using the Pythagoras theorem since it is given that it is a right angled triangle
let us name the triangle as A, B, C with B as right angle
AB^2 + BC^2 = AC^2 ( Pythagoras theorem)
where AB = 4 , BC = 7 , AC = x
10(y+2)-y=2(9y-8)
Mutiply the first bracket by 10
Mutiply the second bracket by 2
(10)(y)(10)(2)= 10y+20
(2)(9y)(2)(-8)= 18y-16
10y+20-y= 18y-16
10y-y+20= 18y-16
9y+20= 18y-16
move 18y to the other side
sign changes from +18y to -18y
9y-18y+20= 18y-18y-16
-9y+20= -16
move +20 to the other side
sign changes from +20 to -20
-9y+20-20=-16-20
-9y= -36
divide by -9
-9y/-9= -36/-9
y= 4
Answer: y= 4