Answer: rose = 7, shrub = 7
Explanation:
First equation 10r + 4s = 98
r = (98-4s) / 10
Second equation 9r + 9s = 126
Substituting
9 (98-4s) / 10 + 9s = 126
9(49-2s) / 5 + 9s = 126
(441-18s) / 5 + 9s = 126
441 - 18s + 45s = 630
441+ 27s = 630
27s = 630 - 441
s = 189 / 27 = 7
Cost of shrub = 7
Cost of rose = (98 - 4s) / 10
= 98-28 = 70 / 10 = 7