After losing 3 baseball cards, Peter gave half of his remaining cards to Bobby. If Peter gave Bobby 9 baseball cards, how many cards did Peter start with? Linear equation:
1
2 (x - 3) = 9

Bobby claims that Peter started with 21 cards. Which statements are true about verifying Bobby’s claim? Check all that apply.

Substitute 21 for x in the original equation.
Substitute any number for x in the original equation.
Bobby’s claim that x = 21 is correct.
The result of verifying Bobby’s work is 9 = 9.
The result of verifying Bobby’s work is 21 = 21.

Math each whole number with a rational,exponential expression

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

The value of x in this system of equations is 1. 3x + y = 9 y = –4x + 10 substitute the value of y in the first equation: combine like terms: apply the subtraction property of equality: apply the division property of equality: 3x + (–4x + 10) = 9 –x + 10 = 9 –x = –1 x = 1 what is the value of y?