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3 years ago

What is the value of the discriminant? 4x2+15x=3x-9

Mathematics

1 answer:

Ray Of Light [21]3 years ago

8 0

Answer:

Step-by-step explanation:

Use the values of a , b , and c to find the discriminant.

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joe weighs 20lbs.less yhantwice jeffs weight.if jeff would gain 10lbs.,then together they wouldweigh 250lbs. how much does each

masya89 [10]

So,

Let x represent Joe's weight and y represent Jeff's weight.

"Joe weighs 20 lbs. less than twice Jeff's weight."
x = 2y - 20

"If Jeff would gain 10 lbs., then together they would weigh 250 lbs."
(y + 10) + x = 250

We now have our two open sentences.
x = 2y - 20
(y + 10) + x = 250

Get rid of parentheses.
x = 2y - 20
x + y + 10 = 250

We will use Elimination by Substitution.
2y - 20 + y + 10 = 250

Collect Like Terms.
3y - 10 = 250

Add 10 to both sides.
3y = 260

Divide both sides by 3.
$Jeff's\ weight = 86 \frac{2}{3} \ lbs.$

Substitute again.
$x = 2(86 \frac{2}{3} )-20$

Multiply.
$x = 173 \frac{1}{3} -20$

Subtract.
$Joe's\ weight = 153 \frac{1}{3}\ lbs.$

Check.

"Joe weighs 20 lbs. less than twice Jeff's weight."
Jeff's weight times two is 173 and one-third.
20 lbs. less than that is 153 and one-third lbs. Check.

"If Jeff would gain 10 lbs., then together they would weigh 250 lbs."
86 and two-thirds + 10 = 96 and two-thirds.
96 and two-thirds + 153 and one-third equals 250 lbs. Check.

$Joe's\ weight\ is\ 153 \frac{1}{3} \ lbs.$
$Jeff's\ weight\ is\ 86 \frac{2}{3} \ lbs.$

3 0

3 years ago

Give an algebraic expression to the given verbal expression

patriot [66]

Twice means times 2.

1) 2(ab) gives twice the product of a and b.
2) (2a)b gives the product of twice a and b.

8 0

3 years ago

Two customers went to a post office to buy postcards and large envelopes. Each postcard

astraxan [27]

The right answer is Option A.

Step-by-step explanation:

Let,

x be the postcards

y be the large envelops

According to given statement;

14x+5y=12 Eqn 1

10x+15y=24.80 Eqn 2

Multiplying Eqn 1 by 3;

$3(14x+5y=12)\\42x+15y=36\ \ \ Eqn \ 3$

Subtracting Eqn 2 from Eqn 3;

$(42x+15y)-(10x+15y)=36-24.80\\42x+15y-10x-15y=11.20\\32x=11.20\\$

Dividing both sides by 32

$\frac{32x}{32}=\frac{11.20}{32}\\x=0.35$

Putting x=0.35 in Eqn 1;

$14(0.35)+5y=12\\4.90+5y=12\\5y=12-4.90\\5y=7.10$

Dividing both sides by 5

$\frac{5y}{5}=\frac{7.10}{5}\\y=1.42$

Therefore, one large envelope costs $1.42

The right answer is Option A.

Keywords: linear equations, subtraction

Learn more about linear equations at:

#LearnwithBrainly

4 0

3 years ago

ABC is a tangent to the circle below. O is the centre of the circle. Work out the size of angle 0. Give reasoning to justify you

Delvig [45]

Answer:

Θ = 46°

Step-by-step explanation:

the angle between a tangent and a radius at the point of contact is 90° , so

∠ ABO = 90°

since OB = OD ( radii of circle ) then Δ BOD is isosceles and

∠ OBD = ∠ ODB = 22°

the exterior angle of a triangle is equal to the sum of the 2 opposite interior angles.

∠ AOB is an exterior angle of the triangle , then

∠ AOB = 22° + 22° = 44°

the sum of the 3 angles in Δ AOB = 180° , then

Θ + 44° + 90° = 180°

Θ + 134° = 180° ( subtract 134° from both sides )

Θ = 46°

6 0

2 years ago

Leona answered all the questions on a test. She had 90% of them correct. There were 40 questions in all. How many did she have c

KengaRu [80]

Answer:

The answer is 36

Step-by-step explanation:

Let the number be <em>x</em>

x/40 is her mark

she got 90% mark correct

x/40 x 100 = 90

by cancellation we get 9 x 4 = 36

HOPE THIS HELPS

6 0

3 years ago