Will mark brainliest, i'm having some trouble (question in attachment)

45b^4/32

Step-by-step explanation: First multiply the two fractions

15b^3y(3b)/8y x 4

Multiply 3 by 15

45b^3yb/8y x 4

Raise b to power of 1

45(b^1b^3)y/8y x 4

Use power rule to combine exponents

45b^1+3 y/8y x 4

Simplify

45b^4y/32y

Cancel common factor of y

45b^4/32

the expression (1.26)2t reveals the approximate rate of increases in the number of plants semiannually.

hope this : )