Answer:
Below
Step-by-step explanation:
Let T be triangle, C the circle and S the square.
● T + T + T = 30
● 3T = 30
Divide both sides by 3
● 3T/3 = 30/3
● T = 10
So the triangle has a value of 10.
●30 T + C + C = 20C + S + S = 13T +C ×S/2
Add like terms together
●30 T + 2C = 20C +2S= 13T + C×S/2
Replace T by its value (T=10)
● 300 + 2C = 20C + 2S = 130 + C×S/2
Take only this part 20C + 2S = 130 + C × S/2
● 20C + 2S = 130 + C×S/2 (1)
Take this part (300+2C = 20C+2S) and express S in function of C
● 20C + 2S = 300 + 2C
Divide everything by 2 to make easier
● 10 C + S = 150+ C
● S = 150+C-10C
● S = 150-9C
Replace S by (5-9C) in (1)
● 20C + 2S = 130 + C×S/2
● 20C + 2(150-9C) = 130 +C× (150-9C)/2
● 20C + 300-18C= 130 + C×(75-4.5C)
● 2C + 300 = 130 + 75 -4.5C^2
● 2C +300-130 = 75C - 4.5C^2
● 2C -75C + 170 = -4.5C^2
● -73C + 170 = -4.5C^2
Multiply all the expression by -1
● -4.5C^2 +73C+ 170= 0
This is a quadratic equation, so we will use the discriminant method.
Let Y be the discriminant
● Y = b^2-4ac
● b = 73
● a = -4.5
● c = 170
● Y = 73^2 - 4×(-4.5)×170= 8389
So the equation has two solutions:
● C = (-b +/- √Y) /2a
√Y is approximatively 92
● C = (-73 + / - 92 )/ -9
● C = 18.34 or C = -2.11
Approximatively
● C = 18 or C = -2
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● if C = 18
30T + 2C = 300 + 36 = 336
● if C = -2
30T + 2C = 300-4 = 296
