Solve by transforming into a perfect square trinomial x squared-14x=15

1 answer:

8 0

X^2 - 14 x = 15

(x - 7)^2 - 49 = 15

(x-7)^2 = 64

x - 7 = - or + 8

x = 15 or -1

Just take half o the coefficient of x and subtract it squared as above.

In general

x^2 + ax = b

(x + a/2)^2 - a^2/4 = b

You might be interested in

Suppose a box contains 3 defective light bulbs and 12 good bulbs. two bulbs are chosen from the box without replacement. find th

Mademuasel [1]

The probability that the bulb is good is 12/15.
Since we have taken 1 item out the remaining total is now 14, so the probability of getting a defective bulb is now 3/14.
Now you multiply the probabilities together to get (12/15)(3/14)=(4/5)(3/14)=12/70=6/35

7 0

3 years ago

What is the difference 1 1/2 - 3/4 ?

kaheart [24]

Answer:

19/4

Step-by-step explanation:

3 0

3 years ago

Convert 3.521 g to ___ mg

inna [77]

To convert any unit to it's "milli-" form always multiply the given value by 1000. The new value will be the value of in the "milli-" form.

The question asked to us is to convert 3.521 g to mg (or milligram). Thus, all that we need to do is to multiply 3.521 with 1000 and we will get the corresponding value in milligrams. Thus, in mg, 3.521 g is:

$3.521\times 1000=3521$ mg