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4 years ago

78×13-8×78+26×78-78=

Mathematics

2 answers:

Amanda [17]4 years ago

7 0

Applying BODMAS (Order of operations rule)

Where: B is for brackets

O is for 'of' which means multiplication

D is for division

M is for multiplication

A is for addition

S is for subtraction

We start with addition then we go to addition and finally we subtract.

(78 × 13) - (8 × 78) + (26 × 78) - 78

= 1014 - 624 + 2028 - 78

= 1014 + 2028 - 624 - 78

= 3042 - 624 - 78

=2340

Serjik [45]4 years ago

7 0

Answer:

Step-by-step explanation:

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10. Amina is currently twice as old as her younger brother,

maks197457 [2]

Answer:

When Amina is 18. Saad would be;

k. 14

Step-by-step explanation:

Let "x" represent Anita's current age and let "y" represent Saad's current age, we have;

Anita's age = 2 × Saad's age

Therefore;

x = 2 × y...(1)

In 4 years, we will get;

x + 4 = 1.5 × (y + 4)...(2)

Substituting the value of x in equation (1) into equation (2), we get;

2·y + 4 = 1.5·y + 1.5 × 4 = 1.5·y + 6

2·y + 4 = 1.5·y + 6

2·y - 1.5·y = 6 - 4 = 2

0.5·y = 2

y = 2/0.5 = 4

Saad's current age = y = 4 years

From equation (1), we have;

x = 2 × y = 2 × 4 = 8

Amina's current age = x = 8 years

When Amina is 18, we have;

18 = 10 + 8 = 10 + x

Therefore, Amina would be 18 in 10 years time from now, from which we have;

Saad would be 10 years + y = 10 years + 4 years = 14 years in 10 years from now

Therefore, when Amina would be 18 years in 10 years from now Saad would be 14 years.

6 0

3 years ago

A number is divided by four. The result is divided by

Vikentia [17]

The original number is 24
2 x 3 = 6
6 x 4 = 24
or
24 / 4 = 6
6 / 3 = 2

4 0

3 years ago

Read 2 more answers

Solve the inequality 2x>30+5/4x

insens350 [35]

Answer:

Step-by-step explanation:

$2x > 30+\frac{5}{4x} \\2x-\frac{5}{4x} > 30\\\frac{8x^2-5}{4x} > 30\\case~1\\if~x > 0\\8x^2-5 > 120x\\8x^2-120x > 5\\x^2-15x > \frac{5}{8} \\adding~(-\frac{15}{2} )^2~to~both~sides\\(x-\frac{15}{2} )^2 > \frac{5}{8}+\frac{225}{4} \\(x-\frac{15}{2} )^2 > \frac{455}{8} \\x-\frac{15}{2} < -\sqrt{\frac{455}{8} } \\x < \frac{15}{2}-\sqrt{\frac{455}{8} } \\or~x < 0\\rejected~as~x > 0$

$x-\frac{15}{2} > \sqrt{\frac{455}{8} } \\x > \frac{15}{2} +\sqrt{\frac{455}{8} }$

case~2

$if~x < 0\\8x^2-5 < 120x\\8x^2-120x < 5\\x^2-15x < \frac{5}{8} \\adding~(-\frac{15}{2} )^2\\(x-\frac{15}{2} )^2 < \frac{5}{8} +(-\frac{15}{2} )^2\\|x-\frac{15}{2} | < \frac{5+450}{8} \\-\sqrt{\frac{455}{8} } < x-\frac{15}{2} < \sqrt{\frac{455}{8} } \\\frac{15}{2} -\sqrt{\frac{455}{8} } < x < \frac{15}{2} +\sqrt{\frac{455}{8} } \\but~x < 0\\7.5-\sqrt{\frac{455}{8} } < x < 0$