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3 years ago

What are the mental math steps to find 7(42)

Mathematics

1 answer:

Kaylis [27]3 years ago

8 0

7*40 = 280, 7*2 = 14,
add both and get 280+14 = 294

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What is the rule for the given sequence? 3, 8, 23, 68, 203,

EleoNora [17]

Answer: Add the number previously added multiplied by 3;

+3x, where x is the number that was added previously

Step-by-step explanation:

3+5=8. That's the first equation, where 5 is x. Then the next equation, 8+3x=23. 8+15=23. It works for all of the equations, so that's the pattern.

4 0

2 years ago

Read 2 more answers

Which of the following equations have complex roots?

mestny [16]

Answer:

Step-by-step explanation:

Complex roots of quadratic functions occur when the discriminant is negative.

Discriminant

$b^2-4ac\quad\textsf{when}\:\:ax^2+bx+c=0$

Evaluate the discriminant of each of the given equations.

$\textsf{A.} \quad 3x^2+2=0$

$\implies a=3, \quad b=0, \quad c=2$

$\implies b^2-4ac=0^2-4(3)(2)=-24$

As -24 < 0 the equation will have complex roots.

$\textsf{B.} \quad 2x^2+1=7x$

$\implies 2x^2-7x+1=0$

$\implies a=2, \quad b=-7, \quad c=1$

$\implies b^2-4ac= (-7)^2-4(2)(1)=41$

As 41 > 0 the equation does not have complex roots.

$\textsf{C.} \quad 3x^2-1=6x$

$\implies 3x^2-6x-1=0$

$\implies a=3, \quad b=-6, \quad c=-1$

$\implies b^2-4ac=(-6)^2-4(3)(-1)=48$

As 48 > 0 the equation does not have complex roots.

$\textsf{D.} \quad 2x^2-1=5x$

$\implies 2x^2-5x-1=0$

$\implies a=2, \quad b=-5, \quad c=-1$

$\implies b^2-4ac=(-5)^2-4(2)(-1)=33$

As 33 > 0 the equation does not have complex roots.

Learn more about discriminants here:

brainly.com/question/27444516

brainly.com/question/27869538

Learn more about complex roots here:

brainly.com/question/26344541

6 0

2 years ago

Find the Area of the Shaded Region.

BaLLatris [955]

Area of rectangle is length x width
area of smaller rectangle
9x5=45
area of large rectangle
11x7=77
77-45=32

5 0

2 years ago

Read 2 more answers

Evaluate 0.4x + 6.1 for x = -5

Law Incorporation [45]

Answer:

the answer is 4.1

Step-by-step explanation:

use mathwa or cynmath next time for a quicker answer

4 0

2 years ago

Which of the following number would have digit 5 at units place?

BARSIC [14]

Answer:

Step-by-step explanation:

cause it's got a 5.....5 x 5 = 25.......make sense

6 0

3 years ago