Answer:
S=157
Step-by-step explanation:
an= a1+(n-1)d
a2=80+(2-1)(-3)
a2=80-3
a2=77
Sn=(a1+an)*n/2
S2=(80+a2)*2/2
S2=(80+77)*1
S2=157
-4(-5-b)=1/3(b+16) Multiply both sides by 3 to get rid of the fraction
-12(-5-b)=b+16 distribute the -12 to get rid of the parenthesis
60+12b=b+16 get the b on the left side and non b values to the right side
11b=-44 solve for b
b=-44/11 simplify the fraction
b=-4
3/5(t+18)=-3(2-t) multiply both sides by 5/3 to get rid of thefraction
t+18=-5(2-t) distribute the -5 to get rid of the parenthises
t+18=-10+5t get the t to the left side and non t values to the right
-4t=-28 solve for t
t=7
Answer: 16,000 litres
Step-by-step explanation:
1/16 of the pool is 2000l
8/16 full is 1/2 of the pool full
1/16 = 2000
8/16 = x
Cross multiply
1/16x = 2000 × 8/16
1/16x = 1000
Multiply both sides by 16
x = 16000
To make the pool half full, 16,000 litres is required.
X/y (3/-1 just look at where the a is if it is o. ln the x axis or y axis then look to see if it's positive or negative