( 1)x+y=2200
(2)[x( 1+6%)+y( 1-5%)]-(x+y)= 1 10
Just solve this equation set, where "[x (1+6%)+y (1-5%)]" is the sum of the number of computers sold by A and B last year;
"x( 1+6%)" means that the number of A computers sold last year is 6% more than the previous year;
"y( 1-5%)" means that the number of B computers sold last year decreased by 5% compared with the previous year;
The solution of binary linear equations is generally to eliminate binary linear equations and change them into one-dimensional linear equations. There are two ways to eliminate elements:
1. Addition and subtraction elimination method: add or subtract two equations in the equation set to eliminate one of the unknowns, so as to achieve the purpose of elimination. The unknowns in the equation set are solved one by one from more to less.
2. Substitution elimination method: an unknown number is eliminated by "substitution", and the equations are transformed into linear equations to solve. This solution is called substitution elimination method, or substitution method for short.
Basic steps to solve equation x:
1, denominator removal: after observing the composition of the equation, multiply the left and right sides of the equation by the least common multiple of each denominator;
2. Remove the brackets: after carefully observing the equation, remove the brackets in the equation, then remove the brackets, and finally remove the braces;
3. Move the term: move all the unknown terms in the equation to the other side of the equation, and all the remaining terms to the other side of the equation;
4. Merging similar terms: By merging the same terms in the equation, the equation is transformed into the form of ax=b(a≠0);
5. Change the coefficient into 1, and divide both sides of the equation by the unknown coefficient A, so that the coefficient before x becomes 1, thus obtaining the solution of the equation.
The calculation formula of sales volume is: sales volume = sales volume ÷ average sales price. Sales volume refers to the number of products sold by an enterprise at a certain stage. Including the quantity of products sold according to the contract supply mode or other supply modes, and the total number of prepayment contracts not delivered in advance during the contract supply cycle. The formula is expressed by mathematical symbols, and there is a certain correlation between various quantities. It is objective and applicable to any problem with similar relevance. In mathematical logic, a formula is a way to express a proposition, which is the grammatical goal of English, but this proposition is likely to depend on the value of the formula random quantity.