4 x^2 + 20 x + 25 = 7
Divide both sides by 4:
x^2 + 5 x + 25/4 = 7/4
Write the left-hand side as a square:
(x + 5/2)^2 = 7/4
Take the square root of both sides:
x + 5/2 = sqrt(7)/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
x = sqrt(7)/2 - 5/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
Answer: x = sqrt(7)/2 - 5/2 or x = -5/2 - sqrt(7)/2
Let x be the price of each pen and y be the price of each pencil. From the given, the equations that are described are,
6x + 8y = 8.50
4x + 4y = 5
Solving for x and y simultaneously gives an answer of x = 0.75 and y = 0.5.
Thus, each pen costs $0.75 and each pencil costs $0.50.
In order to solve for x you have to set x by itself, the first step is to add common like terms for example 3x and 2x are common like terms so lets add them up to get 5x-4=8 now add 4 to both sides because the only way to get rid of a negative is with a positve, now you have 5x=12. your final step is to divide 5 to both sides because the only way to get rid of a multiplication is with a division, this will leave x by itself and your answer will be x=12/5
Hope this helps
4/6 because the bag holds six tiles total so 4 of the 6 are numbered so you would have 4/6 of a chance of picking a numbered tile.