Answer:
21
Step-by-step explanation:
3 times 7 equals 21 and you cant make 21 with 6
(please mark me brainliest if you get it correct)
Answer: 8 where left after the sale
Step-by-step explanation:25% of 64 is 16, 64 plus 16 = 80, 90% of 80 is 72 so 80-72=8cookies were left.
3\4
because the spaces are bigger draw a model and you will see
First term ,a=4 , common difference =4-7=-3, n =50
sum of first 50terms= (50/2)[2×4+(50-1)(-3)]
=25×[8+49]×-3
=25×57×-3
=25× -171
= -42925
derivation of the formula for the sum of n terms
Progression, S
S=a1+a2+a3+a4+...+an
S=a1+(a1+d)+(a1+2d)+(a1+3d)+...+[a1+(n−1)d] → Equation (1)
S=an+an−1+an−2+an−3+...+a1
S=an+(an−d)+(an−2d)+(an−3d)+...+[an−(n−1)d] → Equation (2)
Add Equations (1) and (2)
2S=(a1+an)+(a1+an)+(a1+an)+(a1+an)+...+(a1+an)
2S=n(a1+an)
S=n/2(a1+an)
Substitute an = a1 + (n - 1)d to the above equation, we have
S=n/2{a1+[a1+(n−1)d]}
S=n/2[2a1+(n−1)d]
Rule of trigonometric functions:-
sin a = cos(90 - a)
Here a = 90°.
sin 90 = cos (90 - 90)
1 = cos 0.
cos 0 = 1.
So the cos 0 = 1.