Answer:
x >= 7 OR x < -8
n <= -3 AND n > -6
Step-by-step explanation:
15) 7x - 6 >= 43 OR 10x + 4 < -76
7x >= 43 + 6 OR 10x < -76 - 4
7x >= 49 OR 10x < -80
x >= 7 OR x < -8
you can draw based on this
for >= it is full dot for < it is like circle on the graph
you have to draw both x>= 7 , x < -8 on the same line because it is OR
so both ranges of x are possible
21) 3 + 2n <= -3 AND 1 - 3n < 19
2n <= -3 -3 AND -3n < 19 - 1
2n <= -6 AND -3n < 18
n <= -3 AND 3n > -18
n <= -3 AND n > -6
so it lies between -6 and -3
u can refer pictures below
Subsitution
solve for y in first equation
add 2x to both sides
y=2x+8
sub 2x+8 for y in second equation
16+4x=2(2x+8)
divide both sides by 2
8+2x=2x+8
true
there are infinite solutions for x
therefor infinite soltions for y
there are an infinite number of solutions
Area of trapezium= 1/2 × (a+b) × h
= 1/2 × (12 + 8) × 8
= 1/2 × 20 × 8
= 10 × 8
= 80 cm^3
Hope it helps you
Answer:
0.19512195122
Step-by-step explanation: