Answer:
x = 6 m
Step-by-step explanation:
The area (A) of a trapezium is calculated as
A = 
h (a + b)
where h is the perpendicular height and a, b the parallel bases
Here A = 60, h = 8, a = 9 and b = x , thus
× 8 × (9 + x) = 60, that is
4(9 + x) = 60 ( divide both sides by 4 )
9 + x = 15 ( subtract 9 from both sides )
x = 6 m
Answer:
C 30%
Step-by-step explanation:
87.50/125= 0.70
1-0.7-0.3
Answer:
Sum of the first 15 terms = -405
Step-by-step explanation:
a + 3d = -15 (1)
a + 8d = -30 (2)
Where,
a = first term
d = common difference
n = number of terms
Subtract (1) from (1)
8d - 3d = -30 - (-15)
5d = -30 + 15
5d = -15
d = -15/5
= -3
d = -3
Substitute d = -3 into (1)
a + 3d = -15
a + 3(-3) = -15
a - 9 = -15
a = -15 + 9
a = -6
Sum of the first 15 terms
S = n/2[2a + (n − 1) × d]
= 15/2 {2×-6 + (15-1)-3}
= 7.5{-12 + (14)-3}
= 7.5{ -12 - 42}
= 7.5{-54}
= -405
Sum of the first 15 terms = -405
