Which of these statements about algebra are true?

a. algebra uses abstract symbols to represent concrete elements in the real world.

b. in an algebraic equation, the same variable can represent two different unknowns.

c. many great mathematicians were also philosophers.

d. an algebraic expression contains an equal sign, but an algebraic equation does not.

e. the same variable can represent two different unknowns in two different algebraic expressions.

A.

Step-by-step explanation:

The symbols are usually letters.

The most commonly used are x, y and z.

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.

i believe b is the answer