Answer:
<h2>48</h2>
Step-by-step explanation:
so for every 3 Reid washes there are 4 Elsie washes
the ratio of washing is 3:4
lets add 3 and 4 up
3 + 4 = 7
now lets divide the total number of washes by the added ratio
84/ 7
=12
now we know that 1 part is 12
to find Elsie's part we need to x 12 by how many parts she has got
she washed 4 times
4 x 12
=48
A = 1/2 BH
#17
B = 3 H = 4
A = 1/2 BH
A = 1/2 (3)(4) = 6
#18
B = 6 H = 4
A = 1/2 BH
A = 1/2 (6)(4) = 12
#19
B = 12 H = 8
A = 1/2 BH
A = 1/2 (12)(8) = 48
#20
B = 11 H = 5
A = 1/2 BH
A = 1/2 (11)(5) = 27.5
2x + 4y - 2x - 3y = 22 - 50
y = -28
substitute into the 1st equation to find x