Having trouble with subtracting Negative numbers.

I thought if you subtract 4 - (-8) it would be - 12 instead of (+) 12 can someone explain this to me in detail because I'm alittle confused on subtracting negative numbers.

Consider the system: x=-3y+10 3x+2y=-12 determine if the substitution method or the elimination method would be the better strategy to use. Justify your reasoning using mathematical language.

Anna buys dog food every 6 days and cat food every 9 days. If she buys both kinds of pet food today, in how many days will she next buy both kinds of pet food? A. 3 B. 6 C. 9 D. 18

Harry is at the depot in Dover and has deliveries to make in Edinburgh, Glasgow and Aberdeen. From Dover which of the deliveries is the shortest distance?

Y is directly proportional to x, and y = 216 when x=2 find y when x=7

A woman is looking for a bigger square office. She finds an office twice the area of her current office. if the perimeter of her current office is 88feet, how many square feet is the new office?

Bb had 10 baby's and Declan had 7 baby's how many baby's did Bb have more

The measure of two supplementary angles are 12q-9 and 8q+14 find the measures of the angles

The product of two inductive odd integers

What is the explicite to 19,13,7,1, ...

Jessica makes punch for her party. she uses 1.6 liters of orange juice. the amount of cranberry juice she uses is 0.5 tomes the amount of orange juice, and the amount of apple juice is 0.5 times the amount of cranberry juice.