Answer:
1_ 129 , 51
2_ b
3_ 40
Explanation:
1_ we can represent the bigger angle with x and smaller one with y
and as given, y is smaller than x by 78
so y = x - 78 (1)
as x + y = 180
we put y as we did in (1)
x + x - 78 = 180
so 2x = 258
so x = 129
and y will be 51
2_ from the figure we find the two angles form one angle = 90 degree
3_ from the defenition of complementary angles
m(c) + m(d) = 90
7r + 5 + 8r + 10 = 90
15r + 15 = 90
r = 5
so m(c) will be equal 7*5 + 5 = 40