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]
18 ÷ 3 is 6, which means that Daniel is 6, and there is a 12 year gap between Steve and Daniel.
12 x 2 is 24, so therefore when Steve is 24, Daniel will be 12, so Steve is twice as old as Daniel:)
Answer:
other x values are -5,-4
Step-by-step explanation:
f(x)=0 for x=−6
Apply synthetic division to get the quotient . using that we find other two values of x
-6 1 15 74 120
0 -6 - 54 -120
-------------------------------------------------
1 9 20 0
the quotient is 
now factor the left hand side, product is 20 and sum is 9

So other x values are -5,-4
The number of possibilities for the first one is 50 choose 5, and the number of possibilities for the second one is 60 choose 6. Since 50 choose 5 is 2118760 and 60 choose 6 is 50063860. There are less possible outcomes for state "A" and therefore you have a higher chance of winning.
Answer:
On the right is a circle with centre (0, 0), radius r and (x, y) any point on the circle. Distance between (0,0) and (x, y) equals the radius, r. If the centre is (0, 0), the equation of the circle will be of the form x2 + y2 = r2.