Help two geometric three variable problems...... 10 points!!?

Question

1. A rectangular box has a base that has a perimeter of 30cm, a side called A that has a perimeter of 24cm, and a side called B that has a perimeter of 206cm. Find the dimensions of the box.


2.A combination of tiles in the shapes shown will be used for a mosaic. The shapes chose contain a total of 40 tiles, 72 diagonals, and 153 sides. How many triangles, queares, and pentagons will be used?

remember three variable linear equations...

Answer 1

1. (1) 2L + 2w = 30
(2) 2w + 2h = 24
(3) 2L + 2h = 206
(1) - (3) 2L + 2w = 30
-2L - 2h = -206
(4) 2w + 2h = -176
(2) 2w + 2h = 24
4w = -152
w = -38
(1) 2L + 2w = 30
2L + 2(-38) = 30
2L = 30 + 76
2L = 106
L = 53
(2) 2w + 2h = 24
2(-38) + 2h = 24
-76 + 2h = 24
2h = 100
h = 50

2. (1)T + S + P = 40
(2) 2s + 5P = 72
(3) 3T + 4S + 5O = 153
3X(1) 3T + 3S + 3P = 120
SUBT:(4) S + 2P = 33
2X(4) 2S + 4P = 66
(2) 2S + 5P = 72
SUBT: -P = -6
P = 6
(2) 2S + 5P = 72
2S + 5(6) = 72
2S + 30 = 72
2S = 42
S = 21
(1) T + S + P = 40
T + 21 + 6 = 40
T = 13

Answer 2

we could assume adults use x volume of water and newborn makes use of y volume of water so , 3 x + 5 y = 15 2 x + 4y = 11 fixing those 2 equations 6x + 10 y = 30 ---- eq a million 6x + 12y = 33 ----- eq 2 subtract eq 2 by utilising eq a million 2y = 3 = 3/2 meaning each newborn makes use of three/2 or1.5 gallons of water familiar now to discover value of x placed value of y in any equation 2 x + 4y = 11 2x + 4* 3/2 = 11 2x = 11-6 x = 5/2 = 2.5 gallons is the water utilized by utilising each grownup familiar