The graph shows the solution to which system of equations?
a)
y = x + 2 and y = -x - 4
b)
y = 3x + 7 and y = x + 12
c)
y = 2x - 3 and y = −2x + 1
d)
y = -x + 4 and y = −2x + 5

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Geometry in the diagram, ∠abc is a right angle. ∠dbc = 30°27'40". find the measure of ∠abd.