Answer:
15) 37 16) -5x+13=-112, x=25 23) l=38, w=19
Step-by-step explanation:
15) l=5w+2, 2l+2w=88
2(5w+2)+2w=88
12w+4=88
w=7, l=37
16a) -5x+13=-112
16b) x=25
23) l=2w, 2l+2w=114
2l+l=114
l=38, w=19

We know that, in ∆ABC,
∠A+∠B+∠C = 180°
But the triangle is right angled at C
ie., ∠C = 90°
Therefore, ∠A+∠B+ 90° = 180°
⇒ ∠A + ∠B = 90°
Therefore, <u>cos(A + B) = cos 90º = 0</u>
Answer:
12
Step-by-step explanation:
Answer:
-2
Step-by-step explanation:
-3(2)+4
-6+4
-2