Respuesta :
QUESTION 1
GIVEN:
[tex]long \: base = 3 \times (short \: base)[/tex]
[tex]height = (short \: base) - 2[/tex]
[tex]area = 30 {in}^{2} [/tex]
IMPORTANT EQUATIONS
[tex]trapezoid \: area = \frac{sum \: of \: bases}{2} \times height[/tex]
SOLVE:
[tex]30 = \frac{short + long}{2} (short - 2)[/tex]
[tex]30 = \frac{(short + 3short)}{2} \times (short - 2)[/tex]
[tex]30 = \frac{4short}{2} (short - 2)[/tex]
[tex]30 = 2{(short)}^{2} - 4(short)[/tex]
[tex] {short}^{2} - 2(short) - 15 = 0[/tex]
factor:
[tex](short - 5)(short + 3) = 0[/tex]
[tex]short = 3 \: and \: - 5[/tex]
Negative five is not a reasonable answer, so we focus on the positive three and say that is the length of the short base.
so, the answers:
[tex]short \: base = 3 \: in[/tex]
[tex]long \: base = 3 \times 3 = 9 \: in[/tex]
[tex]height = 3 - 2 = 1 \: in[/tex]
QUESTION 2
GIVEN
convert 3ft to inches.
[tex]l = 32 + w[/tex]
[tex]area = lw = 130 {in}^{2} [/tex]
or
[tex]w = \frac{130}{l} [/tex]
substitute
[tex]l = 32 + \frac{130}{l} [/tex]
solve for l:
[tex] {l}^{2} - 32 l- 130 = 0[/tex]
QUESTION 3
[tex]x(x + 2) = 80[/tex]
solve for X
[tex] {x}^{2} + 2x - 80 = 0[/tex]
[tex](x - 10)(x + 8) = 0[/tex]
[tex]x = 10 \: and \: - 8[/tex]
take the positive value since it's the only one that makes sense in this context.
so the two values are:
[tex]10 \: and \: 8[/tex]
GIVEN:
[tex]long \: base = 3 \times (short \: base)[/tex]
[tex]height = (short \: base) - 2[/tex]
[tex]area = 30 {in}^{2} [/tex]
IMPORTANT EQUATIONS
[tex]trapezoid \: area = \frac{sum \: of \: bases}{2} \times height[/tex]
SOLVE:
[tex]30 = \frac{short + long}{2} (short - 2)[/tex]
[tex]30 = \frac{(short + 3short)}{2} \times (short - 2)[/tex]
[tex]30 = \frac{4short}{2} (short - 2)[/tex]
[tex]30 = 2{(short)}^{2} - 4(short)[/tex]
[tex] {short}^{2} - 2(short) - 15 = 0[/tex]
factor:
[tex](short - 5)(short + 3) = 0[/tex]
[tex]short = 3 \: and \: - 5[/tex]
Negative five is not a reasonable answer, so we focus on the positive three and say that is the length of the short base.
so, the answers:
[tex]short \: base = 3 \: in[/tex]
[tex]long \: base = 3 \times 3 = 9 \: in[/tex]
[tex]height = 3 - 2 = 1 \: in[/tex]
QUESTION 2
GIVEN
convert 3ft to inches.
[tex]l = 32 + w[/tex]
[tex]area = lw = 130 {in}^{2} [/tex]
or
[tex]w = \frac{130}{l} [/tex]
substitute
[tex]l = 32 + \frac{130}{l} [/tex]
solve for l:
[tex] {l}^{2} - 32 l- 130 = 0[/tex]
QUESTION 3
[tex]x(x + 2) = 80[/tex]
solve for X
[tex] {x}^{2} + 2x - 80 = 0[/tex]
[tex](x - 10)(x + 8) = 0[/tex]
[tex]x = 10 \: and \: - 8[/tex]
take the positive value since it's the only one that makes sense in this context.
so the two values are:
[tex]10 \: and \: 8[/tex]