You can solve a system of equations by graphing
The solution of a system of linear equations is the intersection point both graphs
using a graphing tool
the solution is the point (-10,5)
so
x=-10
y=5
the solution is the intersection point both lines
I will solve the system by substitution
we have
-3х – 10у = -20 --------> equation A
-5x — бу = 20 --------> equation B
isolate the variable y in the equation A
10y=-3x+20
y=-0.3x+2 --------> equation C
substitute equation C in equation B
-5x-6(-0.3x+2)=20
solve for x
-5x+1.8x-12=20
-3.2x=20+12
-3.2x=32
x=-10
substitute the value of x in the equation C
y=-0.3x+2
y=-0.3(-10)+2
y=3+2
y=5
the solution is x=-10 and y=5