Area of a rectangular barnyard: A=6x^2+7x-20
A=6(6x^2+7x-20)/6
A=[(6^2)(x^2)+7(6x)-120]/6
A=[(6x)^2+7(6x)-120]/6
A=(6x+15)(6x-8)/6
A=(6x+15)(6x-8)/[(3)(2)]
A=(6x/3+15/3)(6x/2-8/2)
A=(2x+5)(3x-4)
A=bh
b=2x+5; h=3x-4
Answer: The possible dimensions of the barnyard are 2x+5 and 3x-4

8 0

3 years ago

Solve for y 16y^2-25=0

Pepsi [2]

Answer:

$\large\boxed{x=-\dfrac{5}{4}\ \vee\ x=\dfrac{5}{4}}$

Step-by-step explanation:

$16y^2-25=0\\\\METHOD\ 1:\\\text{use}\ a^2-b^2=(a-b)(a+b)\\\\16=4^2\ \text{and}\ 25=5^2\ \text{therefore we have}\\\\4^2y^2-5^2=0\\\\(4y)^2-5^2=0\\\\(4y-5)(4y+5)+0\iff4y-5=0\ \vee\ 4y+5=0\\\\4y-5=0\qquad\text{add 5 to both sides}\\4y=5\qquad\text{divide both sides by 4}\\\boxed{y=\dfrac{5}{4}}\\\\4y+5=0\qquad\text{subtract 5 from both sides}\\4y=-5\qquad\text{divide both sides by 4}\\\boxed{x=-\dfrac{5}{4}}$

$METHOD\ 2:\\\\16y^2-25=0\qquad\text{add 25 to both sides}\\\\16y^2=25\qquad\text{divide both sides by 16}\\\\y^2=\dfrac{25}{16}\to y=\pm\sqrt{\dfrac{25}{26}}\\\\y=-\dfrac{\sqrt{25}}{\sqrt{16}}\ \vee\ x=\dfrac{\sqrt{25}}{\sqrt{16}}\\\\\boxed{y=-\dfrac{5}{4}\ \vee\ x=\dfrac{5}{4}}$

7 0

3 years ago

Read 2 more answers

I also need help with these two

lorasvet [3.4K]

Answer: #13 you need to know that the sides are equal. #14 (7,6)

Step-by-step explanation: #14 in picture

4 0

3 years ago