Answer:
32cm and 28cm
Step-by-step explanation:
Area of a trapezium=0.5 ( sum of parallel sides ) × height
600=0.5( 4+a+a)×20
where a is the length of the shorter side
600÷0.5=(4+2a)×20
1200=(4+2a)×20
1200÷20=4+2a
60=4+2a
60-4=2a
56=2a
56÷2=a
28=a.
since the longer side is 4 cm more than th shorter side , 28 +4=32
It'd be easier to do #18 if y ou were to break it up:
14* (first term + 14th term)
Sum from n=1 to 14 of n = S = ---------------------------------
14 2
14(1+14)
= ---------------- = 7(15) = 105
2
The sum of twice that is 210. The sum of "1 from n=1 to n=14" is just 14.
The final sum is 210 + 14 = 224 (answer)
C.
(I’m pretty sure but if I’m wrong I apologize in advance)
Y = 4 x + 3
<span>y = 4 x + 3/2
</span>no solution :) hope this helps