E:5763

E:5763 (Tudor Rițiu)

Un lot în formă de trapez isoscel are, în metri, baza mică egală cu valoarea numerică a expresieiFailed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E\left(x,y\right) = \frac{\left(x+y\right)^2 - x-y}{x^2-y^2}:\left[ 1 - \frac{1}{x+y}\right]} pentru Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x} a cărei valoare satisface proporția Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \frac{x-2,5}{1\frac{1}{2}} = \frac{x}{2}} iar Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle y} fiind a treia parte din Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x} . Latura neparalelă este de Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \sqrt{3}} ori mai mare decât media geometrică a lui Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle x} și Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle y} . Să determine aria lotului știind că baza mare a trapezului este de 4m.

Soluție:

Avem Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E\left(x,y\right) = \frac{\left(x+y\right)^2 - x-y}{x^2-y^2}:\left[ 1 - \frac{1}{x+y}\right] = \frac{\left(x+y\right)\left(x+y-1\right)}{\left(x+y\right)\left(x-y\right)} \cdot \frac{x+y}{x+y-1}} deci Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle E\left(x,y\right) = \frac{x+y}{x-y}. }