Answer:
expressions which represent exponential decay:
A. 900(0.05)^t
B. 700(0.9)^x
Explanation:
Exponential decay functions has the next form:
y = ab^x
where b < 1
A. 900(0.05)^t , a = 900, b = 0.05, the variable is t instead of x. 0.05 < 1, then it represents exponential decay
B. 700(0.9)^x , a = 700, b = 0.9 < 1, then it represents exponential decay
C. 53(1.75)^(0.3x) = 53(1.75)^(0.3)(1.75)^x, a = 53(1.75)^(0.3), b = 1.75 > 1, then it doesn't represent exponential decay
D. 90(1.2)^t, a = 90, b = 1.2 > 1, then it doesn't represent exponential decay. (the variable is t instead of x)
E. .300(2.4)^(1.2y) = 300(2.4)^(1.2)(2.4)^y, a = 300(2.4)^(1.2), b = 2.4 > 1, then it doesn't represent exponential decay. (the variable is y instead of x)
F. 2x² + 9 , this is a quadratic function, then it doesn't represent exponential decay.
G. 18 – 3y, this is a linear function, then it doesn't represent exponential decay.