Question

7 cos^2 x +7sin^ 2 x​

Answer 1

7 cos² x +7sin² x​ = 7(cos² x + sin² x​) = 7·1 = 7

Answer 2

$7 { \cos(x) }^{2} + 7 { \sin(x) }^{2} \\ 7( { \cos(x) }^{2} + { \sin(x) }^{2} ) \\ { \sin(x) }^{2} + { \cos(x) }^{2} = 1 \\ 7 \times 1 = 7$