(x+ 14)y-xy= 1.96
14y= 1.96
y=0. 14
x(y+ 14)-xy=44
14x=44
x=22/7
2. let the middle number be x.
(x- 1)x(x+ 1)= 120 * 3x
x(x^2- 1)=360x
x^2=36 1
x= 19
These three numbers are 18 19 20.
3. set to b c d.
a+c=3b
(a+b+c+d)/4=2.6+b
(4b+d)/4=2.6+b
b+d/4=2.6+b
d= 10.4