Solve this using substitution.
{y=x+1
{2x+y=7

Y = x + 1so we sub in x + 1 for y in the other equation

2x + y = 7
2x + x + 1 = 7 combine like terms
3x + 1 = 7subtract 1 from both sides
3x = 7 - 1
3x = 6 divide both sides by 3
x = 6/3
x = 2

y = x + 1
y = 2 + 1
y = 3

so ur solution is : (2,3)

Letter a i would say

It equals 1373.5 that’s the solution