The perimeter of a triangle is 80. side one is four times side two. side three is ten less than side one. what are the 3 sides

Let say that:
side one = A
side two = B
side three = C
And also, A+B+C = 80

Then, from that information we can get..
A=4B ; C=A-10... We can get the value of A, but we have to modified some equation.

Let, B=1/4 A (eq.1)
C=A-10 (eq.2)
If we adding eq.1 and eq.2 we get:
B+C = 2A-39/4

Therefore,
A= 80 - (B+C)
A = 80 - 2A + 39/4
3A = 80 + 39/4
3A = 359/4 (Dividing both sides with 3)
A = 359/12 = 29.92
B = 1/4 A = 359/48 = 7.48
C = 359/12 - 10 = 19.92