Help with maths homework please!!!!

Answer:
head of broccoli is 642.9g
Step-by-step explanation:
let p =protein
let s = head of spinach
let b = head of broccoli
broccoli=20%p
spinach=30%p
180gp=20% of s
0.2s = 180gp
s=180/0.2
s=900g
s=1.4 x b
900g=1.4b
900/1.4=b
b=642.9g