Divide I from both sides then subtract r from both sides, too so in the end:
R= (E-r)/I
(2x + 3) • (x + 3)
2x • x = 2x^2
2x • 3 = 6x
3 • x = 3x
3 • 3 = 9
6x and 3x combine to get 9x, which when all written out is equal to your original trinomial.
Answer:
1 in 30
Step-by-step explanation:
1 in 6 chance Mary picks the red marble in the first place. After this there is a 1 in 5 chance her sister picks the blue one. 5 multiplied by 6 is 30.