How many pairs of numbers add up to 11? l have used calculation find their is 6 pairs but like to know • how could i change how i originally did this activity (include resources and mathematics used)?

2x - 20 = 32 20 - 3x = 8 6x - 8 = 16 -13 - 3x = -10

Submarines control how much they float or sink in the ocean by changing the volume of air and water contained in large ballast tanks. when the tanks are completely full of water, the submarine increases its overall mass and sinks down to the bottom. when the tanks are completely full of air, the submarine reduces its overall mass and floats to the surface. depending on the density of the seawater surrounding the submarine, it will pump seawater in or out of the tanks in order to achieve the same overall density as the sea water and float neutrally in the water. the volume of the submarine never changes. when the tanks are completely full of water, a submarine with a volume of 7.8\times10^3\text{ m}^37.8×10 3 m 3 7, point, 8, times, 10, start superscript, 3, end superscript, space, m, start superscript, 3, end superscript has a total mass of 8\times10^6\text{ kg}8×10 6 kg8, times, 10, start superscript, 6, end superscript, space, k, g. the density of the seawater is 10^3\text{ kg/m}^310 3 kg/m 3 10, start superscript, 3, end superscript, space, k, g, slash, m, start superscript, 3, end superscript. to make that submarine float neutrally, and neither float nor sink in the ocean, what volume of water does that submarine need to subtract from its tanks?

Hey everyone! this question is a challenge question. for 50 points if you wish. all you have to do is answer the correct it has to be correct, in under 50 seconds, and i will make you the ! you want to accept this challenge. i already know! i mean, it's 50 free points! here is the question: 11x2= answer this correct, you get two prizes. don't forget. you only have 50 seconds or it wont happen. get it correct in under 50 seconds! that's not bad. so stop reading this long thing and !