Houses and flats ratio9:5 flats and bungalows 10:5
there are 30 bungalows how many houses is there

108 houses

Step-by-step explanation:

Step 1: ratio of flats to bungalows is 10:5 and the bungalows are 30, therefore:

(10*30)/5 = 60 flats

Step 2: the ratio of houses to flats is 9:5 and the number of flats is 60, therefore

9*60/5 = 108 houses

your answer is  

d.

196.5 m2

step-by-step explanation:

a and c

for infinitely many solutions we require both left and right sides to be equal

distribute and simplify

a

14 - 8x = 20 - 8x - 6 = 14 - 8x ← both sides equal so infinite solutions

b

6x - 54 = 6x - 54 + x = 7x - 54 ← not equal

c

4x + 16 = 4x + 10 + 6 = 4x + 16 ← both sides equal so infinite solutions

d

5x - 40 + 10 = 5x + 10

5x - 30 = 5x + 10 ← not equal