a The sum of a triangle's interior angles is 180 ^(∘). From the figure, we can see that one of the angles is y-18. The remaining two are x and y. By adding these together, we can equate their sum with 180.
x+y+y-18=180
b Using the equation found in Part A and the given equation, we can form a system of equations.
x+y+y-18=180 & (I) 3x-5y=-22 & (II)
Let's solve it using the Substitution Method. To do so, we will start by isolating the x-variable in Equation (I).
The solution to the system of equations, which is the point of intersection of the lines, is (86,56). In the context of the problem, this means that the measures of the missing angles are 86^(∘) and 56^(∘).
