the 43rd term of an arithmetic sequence is -671 and the 52nd term is -806. find the first term and the common difference.

First term = -41.

Common difference = -15.

Step-by-step explanation:

nth term: an = a1 + (n - 1)d  where a = first term and d = the common difference.

-671 = a1 + (43 - 1)d

-806 = a1 +(52 - 1)d

-671  = a1 + 42d

-806 = a1 + 51d

Subtracting ( to eliminate a1):

-671 - (-806) = 42d - 51d

-9d =  135

d = -15

Substitute for d in the first equation:

-671 = a1 + 42*-15

-671 = a1 - 630

a1 = -671 + 630 = -41.

answer: c, the green line

step-by-step explanation:

there is no black line, eliminate b.

simple interest implies periodic payments, but the red line shows no payments, eliminate d.

simple interest has equal payments. if paid say every day, the graph is about a straight line (actually a stairstep).

the yellow line is not straight, eliminate a.

check: the green line is straight, answer is c.

simple interest with positive interest rate gives a straight line sloping up to the right. green line:

g(t) = $100 + ($200-$100) ÷ (20 years) × (t years)

= $100 + (4%/year) × ($100)(t years)

incidentally, the yellow line curving upward represents continuously compounded interest

y = $100 × 2^(t years / (14 assuming the yellow line hits $200 at 14 years. 2^0 is 1, so y(0) = $100; 2^(14/14) is 2, so y(14) = $200.

his first public project he is asked to create a small scale drawing. the garden is a right triangle with base 25m and height 30m. are you trying to solve for the last side/hypotenuse? the irrational form of the answer would be 5\sqrt{61}